leetcode-problems

String

0022-generate-parentheses
0208-implement-trie-prefix-tree
0271-encode-and-decode-strings
0344-reverse-string
0409-longest-palindrome
0424-longest-repeating-character-replacement
0647-palindromic-substrings
0648-replace-words
1044-find-common-characters
2572-append-characters-to-string-to-make-subsequence
2890-count-substrings-without-repeating-character
3379-score-of-a-string

Array

0053-maximum-subarray
0066-plus-one
0075-sort-colors
0215-kth-largest-element-in-an-array
0220-contains-duplicate-iii
0238-product-of-array-except-self
0239-sliding-window-maximum
0252-meeting-rooms
0253-meeting-rooms-ii
0271-encode-and-decode-strings
0307-range-sum-query-mutable
0322-coin-change
0330-patching-array
0435-non-overlapping-intervals
0502-ipo
0523-continuous-subarray-sum
0648-replace-words
0739-daily-temperatures
0876-hand-of-straights
1014-k-closest-points-to-origin
1037-minimum-number-of-k-consecutive-bit-flips
1044-find-common-characters
1056-capacity-to-ship-packages-within-d-days
1127-last-stone-weight
1217-relative-sort-array
1605-minimum-number-of-days-to-make-m-bouquets
1675-magnetic-force-between-two-balls
1719-put-boxes-into-the-warehouse-ii
2071-longest-common-subsequence-between-sorted-arrays
3461-find-the-minimum-area-to-cover-all-ones-i
3471-minimum-average-of-smallest-and-largest-elements

Hash Table

0208-implement-trie-prefix-tree
0359-logger-rate-limiter
0409-longest-palindrome
0424-longest-repeating-character-replacement
0523-continuous-subarray-sum
0648-replace-words
0876-hand-of-straights
1044-find-common-characters
1217-relative-sort-array
2071-longest-common-subsequence-between-sorted-arrays
2890-count-substrings-without-repeating-character

Counting

2071-longest-common-subsequence-between-sorted-arrays

Two Pointers

0075-sort-colors
0253-meeting-rooms-ii
0295-find-median-from-data-stream
0344-reverse-string
0633-sum-of-square-numbers
0647-palindromic-substrings
2572-append-characters-to-string-to-make-subsequence
3471-minimum-average-of-smallest-and-largest-elements

Design

0208-implement-trie-prefix-tree
0271-encode-and-decode-strings
0295-find-median-from-data-stream
0307-range-sum-query-mutable
0359-logger-rate-limiter

Trie

0208-implement-trie-prefix-tree
0648-replace-words

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0253-meeting-rooms-ii
0295-find-median-from-data-stream
0502-ipo
1014-k-closest-points-to-origin
1127-last-stone-weight
2379-maximum-total-importance-of-roads

Divide and Conquer

0053-maximum-subarray
0215-kth-largest-element-in-an-array
1014-k-closest-points-to-origin
1285-balance-a-binary-search-tree

Dynamic Programming

0022-generate-parentheses
0053-maximum-subarray
0322-coin-change
0435-non-overlapping-intervals
0647-palindromic-substrings

Greedy

0253-meeting-rooms-ii
0330-patching-array
0409-longest-palindrome
0435-non-overlapping-intervals
0502-ipo
0876-hand-of-straights
1285-balance-a-binary-search-tree
1719-put-boxes-into-the-warehouse-ii
2379-maximum-total-importance-of-roads
2572-append-characters-to-string-to-make-subsequence

Sorting

0075-sort-colors
0215-kth-largest-element-in-an-array
0220-contains-duplicate-iii
0252-meeting-rooms
0253-meeting-rooms-ii
0295-find-median-from-data-stream
0435-non-overlapping-intervals
0502-ipo
0876-hand-of-straights
1014-k-closest-points-to-origin
1217-relative-sort-array
1675-magnetic-force-between-two-balls
1719-put-boxes-into-the-warehouse-ii
2379-maximum-total-importance-of-roads
3471-minimum-average-of-smallest-and-largest-elements

Math

0066-plus-one
0523-continuous-subarray-sum
0633-sum-of-square-numbers
1014-k-closest-points-to-origin

Geometry

1014-k-closest-points-to-origin

Quickselect

0215-kth-largest-element-in-an-array
1014-k-closest-points-to-origin

Prefix Sum

0238-product-of-array-except-self
0253-meeting-rooms-ii
0523-continuous-subarray-sum
1037-minimum-number-of-k-consecutive-bit-flips

Backtracking

0022-generate-parentheses

Stack

0739-daily-temperatures

Monotonic Stack

0739-daily-temperatures

Sliding Window

0220-contains-duplicate-iii
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
1037-minimum-number-of-k-consecutive-bit-flips
2890-count-substrings-without-repeating-character

Counting Sort

1217-relative-sort-array

Data Stream

0295-find-median-from-data-stream
0359-logger-rate-limiter

Binary Indexed Tree

0307-range-sum-query-mutable

Segment Tree

0307-range-sum-query-mutable

Linked List

0021-merge-two-sorted-lists

Recursion

0021-merge-two-sorted-lists

Binary Search

0633-sum-of-square-numbers
1056-capacity-to-ship-packages-within-d-days
1605-minimum-number-of-days-to-make-m-bouquets
1675-magnetic-force-between-two-balls

Queue

0239-sliding-window-maximum
1037-minimum-number-of-k-consecutive-bit-flips

Monotonic Queue

0239-sliding-window-maximum

Bucket Sort

0220-contains-duplicate-iii

Ordered Set

0220-contains-duplicate-iii

Bit Manipulation

1037-minimum-number-of-k-consecutive-bit-flips

Tree

0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Depth-First Search

0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Binary Search Tree

0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Binary Tree

0975-range-sum-of-bst
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Breadth-First Search

0322-coin-change

Matrix

3461-find-the-minimum-area-to-cover-all-ones-i

Graph

2379-maximum-total-importance-of-roads

LeetCode Topics

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0061-rotate-list
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0432-all-oone-data-structure
0460-lfu-cache
0716-max-stack
0725-split-linked-list-in-parts
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0766-flatten-a-multilevel-doubly-linked-list
0816-design-hashset
0817-design-hashmap
0859-design-circular-deque
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
1484-linked-list-in-binary-tree
1582-design-browser-history
1774-add-two-polynomials-represented-as-linked-lists
1905-design-authentication-manager
1982-remove-duplicates-from-an-unsorted-linked-list
2182-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2299-merge-nodes-in-between-zeros
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Depth-First Search

0079-word-search
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0133-clone-graph
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0156-binary-tree-upside-down
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0211-design-add-and-search-words-data-structure
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0261-graph-valid-tree
0269-alien-dictionary
0272-closest-binary-search-tree-value-ii
0297-serialize-and-deserialize-binary-tree
0302-smallest-rectangle-enclosing-black-pixels
0314-binary-tree-vertical-order-traversal
0323-number-of-connected-components-in-an-undirected-graph
0332-reconstruct-itinerary
0339-nested-list-weight-sum
0341-flatten-nested-list-iterator
0364-nested-list-weight-sum-ii
0366-find-leaves-of-binary-tree
0386-lexicographical-numbers
0417-pacific-atlantic-water-flow
0419-battleships-in-a-board
0472-concatenated-words
0543-diameter-of-binary-tree
0547-number-of-provinces
0565-array-nesting
0572-subtree-of-another-tree
0653-two-sum-iv-input-is-a-bst
0666-path-sum-iv
0671-second-minimum-node-in-a-binary-tree
0684-redundant-connection
0695-max-area-of-island
0721-accounts-merge
0744-network-delay-time
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0766-flatten-a-multilevel-doubly-linked-list
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
0803-cheapest-flights-within-k-stops
0854-making-a-large-island
0893-all-nodes-distance-k-in-binary-tree
0975-range-sum-of-bst
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1079-sum-of-root-to-leaf-binary-numbers
1093-recover-a-tree-from-preorder-traversal
1190-smallest-common-region
1218-lowest-common-ancestor-of-deepest-leaves
1350-remove-sub-folders-from-the-filesystem
1387-find-elements-in-a-contaminated-binary-tree
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
1544-count-good-nodes-in-binary-tree
1653-number-of-good-leaf-nodes-pairs
1691-minimum-number-of-days-to-disconnect-island
1780-lowest-common-ancestor-of-a-binary-tree-ii
1816-lowest-common-ancestor-of-a-binary-tree-iv
1883-find-distance-in-a-binary-tree
2009-longest-word-with-all-prefixes
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2493-reverse-odd-levels-of-binary-tree
2677-cousins-in-binary-tree-ii
2793-count-the-number-of-complete-components
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3809-properties-graph

Doubly-Linked List

0146-lru-cache
0432-all-oone-data-structure
0460-lfu-cache
0716-max-stack
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0766-flatten-a-multilevel-doubly-linked-list
1582-design-browser-history
1905-design-authentication-manager

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0127-word-ladder
0133-clone-graph
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0261-graph-valid-tree
0269-alien-dictionary
0286-walls-and-gates
0297-serialize-and-deserialize-binary-tree
0302-smallest-rectangle-enclosing-black-pixels
0314-binary-tree-vertical-order-traversal
0317-shortest-distance-from-all-buildings
0322-coin-change
0323-number-of-connected-components-in-an-undirected-graph
0339-nested-list-weight-sum
0364-nested-list-weight-sum-ii
0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0433-minimum-genetic-mutation
0547-number-of-provinces
0653-two-sum-iv-input-is-a-bst
0684-redundant-connection
0695-max-area-of-island
0721-accounts-merge
0744-network-delay-time
0803-cheapest-flights-within-k-stops
0833-bus-routes
0854-making-a-large-island
0893-all-nodes-distance-k-in-binary-tree
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1190-smallest-common-region
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1544-count-good-nodes-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
1883-find-distance-in-a-binary-tree
2171-second-minimum-time-to-reach-destination
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2588-maximum-number-of-points-from-grid-queries
2677-cousins-in-binary-tree-ii
2793-count-the-number-of-complete-components
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3809-properties-graph

Graph

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0261-graph-valid-tree
0269-alien-dictionary
0277-find-the-celebrity
0323-number-of-connected-components-in-an-undirected-graph
0332-reconstruct-itinerary
0547-number-of-provinces
0684-redundant-connection
0744-network-delay-time
0803-cheapest-flights-within-k-stops
0984-most-stones-removed-with-same-row-or-column
1325-path-with-maximum-probability
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
1706-min-cost-to-connect-all-points
2090-number-of-ways-to-arrive-at-destination
2171-second-minimum-time-to-reach-destination
2220-find-all-possible-recipes-from-given-supplies
2230-minimum-cost-to-reach-city-with-discounts
2506-minimize-maximum-value-in-a-grid
2793-count-the-number-of-complete-components
2880-find-the-closest-marked-node
3235-minimum-cost-to-convert-string-i
3348-minimum-cost-walk-in-weighted-graph
3809-properties-graph

Topological Sort

0207-course-schedule
0210-course-schedule-ii
0269-alien-dictionary
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
2506-minimize-maximum-value-in-a-grid

Union Find

0128-longest-consecutive-sequence
0200-number-of-islands
0261-graph-valid-tree
0323-number-of-connected-components-in-an-undirected-graph
0547-number-of-provinces
0684-redundant-connection
0695-max-area-of-island
0721-accounts-merge
0854-making-a-large-island
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1058-lexicographically-smallest-equivalent-string
1085-the-earliest-moment-when-everyone-become-friends
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
1706-min-cost-to-connect-all-points
2506-minimize-maximum-value-in-a-grid
2588-maximum-number-of-points-from-grid-queries
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph
3809-properties-graph

Tree

0100-same-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0156-binary-tree-upside-down
0173-binary-search-tree-iterator
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0255-verify-preorder-sequence-in-binary-search-tree
0272-closest-binary-search-tree-value-ii
0297-serialize-and-deserialize-binary-tree
0314-binary-tree-vertical-order-traversal
0341-flatten-nested-list-iterator
0366-find-leaves-of-binary-tree
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0653-two-sum-iv-input-is-a-bst
0666-path-sum-iv
0671-second-minimum-node-in-a-binary-tree
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
0789-kth-largest-element-in-a-stream
0791-split-bst
0893-all-nodes-distance-k-in-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0975-range-sum-of-bst
1029-vertical-order-traversal-of-a-binary-tree
1079-sum-of-root-to-leaf-binary-numbers
1093-recover-a-tree-from-preorder-traversal
1190-smallest-common-region
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1484-linked-list-in-binary-tree
1544-count-good-nodes-in-binary-tree
1653-number-of-good-leaf-nodes-pairs
1780-lowest-common-ancestor-of-a-binary-tree-ii
1790-lowest-common-ancestor-of-a-binary-tree-iii
1816-lowest-common-ancestor-of-a-binary-tree-iv
1883-find-distance-in-a-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2306-create-binary-tree-from-descriptions
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii
3307-find-the-maximum-sum-of-node-values
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Binary Search Tree

0004-median-of-two-sorted-arrays
0034-find-first-and-last-position-of-element-in-sorted-array
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0173-binary-search-tree-iterator
0235-lowest-common-ancestor-of-a-binary-search-tree
0255-verify-preorder-sequence-in-binary-search-tree
0268-missing-number
0272-closest-binary-search-tree-value-ii
0275-h-index-ii
0300-longest-increasing-subsequence
0302-smallest-rectangle-enclosing-black-pixels
0350-intersection-of-two-arrays-ii
0362-design-hit-counter
0653-two-sum-iv-input-is-a-bst
0658-find-k-closest-elements
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0745-find-smallest-letter-greater-than-target
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0789-kth-largest-element-in-a-stream
0791-split-bst
0892-shortest-subarray-with-sum-at-least-k
0912-random-pick-with-weight
0975-range-sum-of-bst
1023-time-based-key-value-store
1046-max-consecutive-ones-iii
1051-shortest-way-to-form-string
1060-longest-repeating-substring
1149-intersection-of-three-sorted-arrays
1352-maximum-profit-in-job-scheduling
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1766-minimum-number-of-removals-to-make-mountain-array
1966-frequency-of-the-most-frequent-element
2006-find-the-student-that-will-replace-the-chalk
2045-cutting-ribbons
2180-maximum-number-of-tasks-you-can-assign
2280-count-good-triplets-in-an-array
2394-count-subarrays-with-score-less-than-k
2498-smallest-subarrays-with-maximum-bitwise-or
2614-maximum-count-of-positive-integer-and-negative-integer
2640-maximum-number-of-integers-to-choose-from-a-range-i
2665-minimum-time-to-repair-cars
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
3081-minimum-array-length-after-pair-removals
3267-find-longest-special-substring-that-occurs-thrice-i

Recursion

0002-add-two-numbers
0024-swap-nodes-in-pairs
0050-powx-n
0241-different-ways-to-add-parentheses
0255-verify-preorder-sequence-in-binary-search-tree
0273-integer-to-english-words
0791-split-bst
1197-parsing-a-boolean-expression
1667-find-kth-bit-in-nth-binary-string
1951-find-the-winner-of-the-circular-game
2050-count-good-numbers

Binary Tree

0100-same-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0156-binary-tree-upside-down
0173-binary-search-tree-iterator
0226-invert-binary-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0255-verify-preorder-sequence-in-binary-search-tree
0272-closest-binary-search-tree-value-ii
0297-serialize-and-deserialize-binary-tree
0314-binary-tree-vertical-order-traversal
0366-find-leaves-of-binary-tree
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0653-two-sum-iv-input-is-a-bst
0666-path-sum-iv
0671-second-minimum-node-in-a-binary-tree
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0789-kth-largest-element-in-a-stream
0791-split-bst
0893-all-nodes-distance-k-in-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0975-range-sum-of-bst
1029-vertical-order-traversal-of-a-binary-tree
1079-sum-of-root-to-leaf-binary-numbers
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1484-linked-list-in-binary-tree
1544-count-good-nodes-in-binary-tree
1653-number-of-good-leaf-nodes-pairs
1780-lowest-common-ancestor-of-a-binary-tree-ii
1790-lowest-common-ancestor-of-a-binary-tree-iii
1816-lowest-common-ancestor-of-a-binary-tree-iv
1883-find-distance-in-a-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2306-create-binary-tree-from-descriptions
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2677-cousins-in-binary-tree-ii

Hash Table

0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0017-letter-combinations-of-a-phone-number
0036-valid-sudoku
0041-first-missing-positive
0049-group-anagrams
0073-set-matrix-zeroes
0127-word-ladder
0128-longest-consecutive-sequence
0133-clone-graph
0138-copy-list-with-random-pointer
0139-word-break
0141-linked-list-cycle
0146-lru-cache
0149-max-points-on-a-line
0166-fraction-to-recurring-decimal
0187-repeated-dna-sequences
0202-happy-number
0205-isomorphic-strings
0244-shortest-word-distance-ii
0264-ugly-number-ii
0266-palindrome-permutation
0268-missing-number
0290-word-pattern
0311-sparse-matrix-multiplication
0314-binary-tree-vertical-order-traversal
0325-maximum-size-subarray-sum-equals-k
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0359-logger-rate-limiter
0380-insert-delete-getrandom-o1
0387-first-unique-character-in-a-string
0398-random-pick-index
0421-maximum-xor-of-two-numbers-in-an-array
0432-all-oone-data-structure
0433-minimum-genetic-mutation
0448-find-all-numbers-disappeared-in-an-array
0460-lfu-cache
0496-next-greater-element-i
0500-keyboard-row
0560-subarray-sum-equals-k
0567-permutation-in-string
0653-two-sum-iv-input-is-a-bst
0666-path-sum-iv
0721-accounts-merge
0726-number-of-atoms
0768-partition-labels
0778-reorganize-string
0797-rabbits-in-forest
0816-design-hashset
0817-design-hashmap
0833-bus-routes
0893-all-nodes-distance-k-in-binary-tree
0905-length-of-longest-fibonacci-subsequence
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0952-word-subsets
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1023-time-based-key-value-store
1029-vertical-order-traversal-of-a-binary-tree
1055-pairs-of-songs-with-total-durations-divisible-by-60
1074-high-five
1084-find-k-length-substrings-with-no-repeated-characters
1098-largest-unique-number
1108-analyze-user-website-visit-pattern
1147-flip-columns-for-maximum-number-of-equal-rows
1149-intersection-of-three-sorted-arrays
1190-smallest-common-region
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1256-rank-transform-of-an-array
1366-first-unique-number
1387-find-elements-in-a-contaminated-binary-tree
1473-find-the-longest-substring-containing-vowels-in-even-counts
1500-count-largest-group
1502-construct-k-palindrome-strings
1556-make-two-arrays-equal-by-reversing-subarrays
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1715-split-a-string-into-the-max-number-of-unique-substrings
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1790-lowest-common-ancestor-of-a-binary-tree-iii
1816-lowest-common-ancestor-of-a-binary-tree-iv
1883-find-distance-in-a-binary-tree
1903-design-most-recently-used-queue
1905-design-authentication-manager
1915-check-if-one-string-swap-can-make-strings-equal
1982-remove-duplicates-from-an-unsorted-linked-list
2003-distinct-numbers-in-each-subarray
2079-delete-duplicate-folders-in-system
2163-kth-distinct-string-in-an-array
2169-simple-bank-system
2220-find-all-possible-recipes-from-given-supplies
2247-number-of-unique-flavors-after-sharing-k-candies
2303-unique-substrings-with-equal-digit-frequency
2306-create-binary-tree-from-descriptions
2308-divide-array-into-equal-pairs
2331-intersection-of-multiple-arrays
2434-design-a-number-container-system
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2502-sort-the-people
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2581-divide-players-into-teams-of-equal-skill
2599-take-k-of-each-character-from-left-and-right
2626-count-the-number-of-good-subarrays
2640-maximum-number-of-integers-to-choose-from-a-range-i
2677-cousins-in-binary-tree-ii
2685-first-completely-painted-row-or-column
2707-merge-two-2d-arrays-by-summing-values
2755-extra-characters-in-a-string
2856-count-complete-subarrays-in-an-array
2888-minimum-index-of-a-valid-split
2915-count-of-interesting-subarrays
3081-minimum-array-length-after-pair-removals
3227-find-missing-and-repeated-values
3247-number-of-same-end-substrings
3254-number-of-divisible-triplet-sums
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix
3434-find-the-number-of-distinct-colors-among-the-balls
3445-lexicographically-minimum-string-after-removing-stars
3474-better-compression-of-string
3501-delete-nodes-from-linked-list-present-in-array
3519-find-the-number-of-winning-players
3548-find-the-count-of-good-integers
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3594-identify-the-largest-outlier-in-an-array
3753-maximum-difference-between-even-and-odd-frequency-i
3809-properties-graph

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0042-trapping-rain-water
0061-rotate-list
0088-merge-sorted-array
0141-linked-list-cycle
0202-happy-number
0244-shortest-word-distance-ii
0251-flatten-2d-vector
0272-closest-binary-search-tree-value-ii
0277-find-the-celebrity
0283-move-zeroes
0350-intersection-of-two-arrays-ii
0360-sort-transformed-array
0408-valid-word-abbreviation
0443-string-compression
0567-permutation-in-string
0653-two-sum-iv-input-is-a-bst
0658-find-k-closest-elements
0680-valid-palindrome-ii
0719-find-k-th-smallest-pair-distance
0768-partition-labels
0868-push-dominoes
0874-backspace-string-compare
0908-middle-of-the-linked-list
0979-di-string-match
1051-shortest-way-to-form-string
1165-meeting-scheduler
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1774-add-two-polynomials-represented-as-linked-lists
1790-lowest-common-ancestor-of-a-binary-tree-iii
1894-merge-strings-alternately
1923-sentence-similarity-iii
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2265-partition-array-according-to-given-pivot
2551-apply-operations-to-an-array
2581-divide-players-into-teams-of-equal-skill
2588-maximum-number-of-points-from-grid-queries
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3081-minimum-array-length-after-pair-removals
3526-minimum-number-of-flips-to-make-binary-grid-palindromic-i

Array

0004-median-of-two-sorted-arrays
0011-container-with-most-water
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0034-find-first-and-last-position-of-element-in-sorted-array
0036-valid-sudoku
0039-combination-sum
0040-combination-sum-ii
0041-first-missing-positive
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0049-group-anagrams
0051-n-queens
0055-jump-game
0056-merge-intervals
0059-spiral-matrix-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0078-subsets
0079-word-search
0088-merge-sorted-array
0090-subsets-ii
0118-pascals-triangle
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0128-longest-consecutive-sequence
0134-gas-station
0139-word-break
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0179-largest-number
0198-house-robber
0200-number-of-islands
0204-count-primes
0221-maximal-square
0238-product-of-array-except-self
0243-shortest-word-distance
0244-shortest-word-distance-ii
0251-flatten-2d-vector
0255-verify-preorder-sequence-in-binary-search-tree
0256-paint-house
0265-paint-house-ii
0268-missing-number
0269-alien-dictionary
0274-h-index
0275-h-index-ii
0283-move-zeroes
0286-walls-and-gates
0300-longest-increasing-subsequence
0302-smallest-rectangle-enclosing-black-pixels
0309-best-time-to-buy-and-sell-stock-with-cooldown
0311-sparse-matrix-multiplication
0317-shortest-distance-from-all-buildings
0322-coin-change
0325-maximum-size-subarray-sum-equals-k
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0360-sort-transformed-array
0362-design-hit-counter
0373-find-k-pairs-with-smallest-sums
0380-insert-delete-getrandom-o1
0407-trapping-rain-water-ii
0414-third-maximum-number
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0419-battleships-in-a-board
0421-maximum-xor-of-two-numbers-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0465-optimal-account-balancing
0472-concatenated-words
0485-max-consecutive-ones
0487-max-consecutive-ones-ii
0494-target-sum
0496-next-greater-element-i
0500-keyboard-row
0518-coin-change-ii
0539-minimum-time-difference
0560-subarray-sum-equals-k
0565-array-nesting
0566-reshape-the-matrix
0605-can-place-flowers
0624-maximum-distance-in-arrays
0636-exclusive-time-of-functions
0658-find-k-closest-elements
0666-path-sum-iv
0695-max-area-of-island
0719-find-k-th-smallest-pair-distance
0721-accounts-merge
0729-my-calendar-i
0731-my-calendar-ii
0735-asteroid-collision
0745-find-smallest-letter-greater-than-target
0797-rabbits-in-forest
0816-design-hashset
0817-design-hashmap
0833-bus-routes
0854-making-a-large-island
0859-design-circular-deque
0890-lemonade-change
0892-shortest-subarray-with-sum-at-least-k
0905-length-of-longest-fibonacci-subsequence
0906-walking-robot-simulation
0912-random-pick-with-weight
0921-spiral-matrix-iii
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0952-word-subsets
0979-di-string-match
0999-regions-cut-by-slashes
1036-rotting-oranges
1046-max-consecutive-ones-iii
1055-pairs-of-songs-with-total-durations-divisible-by-60
1074-high-five
1085-the-earliest-moment-when-everyone-become-friends
1098-largest-unique-number
1107-minimum-swaps-to-group-all-1s-together
1108-analyze-user-website-visit-pattern
1147-flip-columns-for-maximum-number-of-equal-rows
1149-intersection-of-three-sorted-arrays
1165-meeting-scheduler
1166-toss-strange-coins
1190-smallest-common-region
1196-filling-bookcase-shelves
1227-number-of-equivalent-domino-pairs
1240-stone-game-ii
1256-rank-transform-of-an-array
1293-three-consecutive-odds
1325-path-with-maximum-probability
1329-minimum-cost-to-move-chips-to-the-same-position
1333-sort-the-jumbled-numbers
1345-perform-string-shifts
1350-remove-sub-folders-from-the-filesystem
1352-maximum-profit-in-job-scheduling
1366-first-unique-number
1435-xor-queries-of-a-subarray
1477-product-of-the-last-k-numbers
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1496-lucky-numbers-in-a-matrix
1497-design-a-stack-with-increment-operation
1511-count-number-of-teams
1514-minimum-value-to-get-positive-step-by-step-sum
1524-string-matching-in-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1582-design-browser-history
1615-range-sum-of-sorted-subarray-sums
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1620-check-if-array-pairs-are-divisible-by-k
1631-number-of-sub-arrays-with-odd-sum
1656-count-good-triplets
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1691-minimum-number-of-days-to-disconnect-island
1693-sum-of-all-odd-length-subarrays
1694-make-sum-divisible-by-p
1706-min-cost-to-connect-all-points
1720-crawler-log-folder
1741-sort-array-by-increasing-frequency
1755-defuse-the-bomb
1766-minimum-number-of-removals-to-make-mountain-array
1786-count-the-number-of-consistent-strings
1803-average-waiting-time
1829-maximum-units-on-a-truck
1849-maximum-absolute-sum-of-any-subarray
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1903-design-most-recently-used-queue
1923-sentence-similarity-iii
1927-maximum-ascending-subarray-sum
1951-find-the-winner-of-the-circular-game
1966-frequency-of-the-most-frequent-element
1972-rotating-the-box
1993-sum-of-all-subset-xor-totals
2003-distinct-numbers-in-each-subarray
2006-find-the-student-that-will-replace-the-chalk
2012-process-tasks-using-servers
2045-cutting-ribbons
2067-maximum-number-of-points-with-cost
2079-delete-duplicate-folders-in-system
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2160-minimum-operations-to-make-a-uni-value-grid
2163-kth-distinct-string-in-an-array
2169-simple-bank-system
2170-count-number-of-maximum-bitwise-or-subsets
2180-maximum-number-of-tasks-you-can-assign
2220-find-all-possible-recipes-from-given-supplies
2247-number-of-unique-flavors-after-sharing-k-candies
2249-count-the-hidden-sequences
2255-minimum-swaps-to-group-all-1s-together-ii
2262-solving-questions-with-brainpower
2265-partition-array-according-to-given-pivot
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2292-counting-words-with-a-given-prefix
2306-create-binary-tree-from-descriptions
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2324-find-triangular-sum-of-an-array
2331-intersection-of-multiple-arrays
2354-minimum-health-to-beat-game
2394-count-subarrays-with-score-less-than-k
2448-count-number-of-bad-pairs
2465-shifting-letters-ii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2478-longest-nice-subarray
2479-meeting-rooms-iii
2494-sum-of-prefix-scores-of-strings
2498-smallest-subarrays-with-maximum-bitwise-or
2502-sort-the-people
2503-longest-subarray-with-maximum-bitwise-and
2506-minimize-maximum-value-in-a-grid
2527-count-subarrays-with-fixed-bounds
2551-apply-operations-to-an-array
2581-divide-players-into-teams-of-equal-skill
2588-maximum-number-of-points-from-grid-queries
2614-maximum-count-of-positive-integer-and-negative-integer
2626-count-the-number-of-good-subarrays
2640-maximum-number-of-integers-to-choose-from-a-range-i
2665-minimum-time-to-repair-cars
2674-make-the-prefix-sum-non-negative
2681-put-marbles-in-bags
2685-first-completely-painted-row-or-column
2690-house-robber-iv
2691-count-vowel-strings-in-ranges
2692-take-gifts-from-the-richest-pile
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2756-buy-two-chocolates
2823-the-knights-tour
2846-robot-collisions
2856-count-complete-subarrays-in-an-array
2868-continuous-subarrays
2880-find-the-closest-marked-node
2888-minimum-index-of-a-valid-split
2915-count-of-interesting-subarrays
3001-apply-operations-to-maximize-score
3081-minimum-array-length-after-pair-removals
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3227-find-missing-and-repeated-values
3235-minimum-cost-to-convert-string-i
3247-number-of-same-end-substrings
3254-number-of-divisible-triplet-sums
3307-find-the-maximum-sum-of-node-values
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix
3348-minimum-cost-walk-in-weighted-graph
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3434-find-the-number-of-distinct-colors-among-the-balls
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3501-delete-nodes-from-linked-list-present-in-array
3504-minimum-moves-to-get-a-peaceful-board
3519-find-the-number-of-winning-players
3522-find-the-power-of-k-size-subarrays-i
3526-minimum-number-of-flips-to-make-binary-grid-palindromic-i
3594-identify-the-largest-outlier-in-an-array
3606-minimum-element-after-replacement-with-digit-sum
3685-count-subarrays-of-length-three-with-a-condition
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3780-permutations-iii
3809-properties-graph
3949-minimum-number-of-primes-to-sum-to-target

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0047-permutations-ii
0051-n-queens
0078-subsets
0079-word-search
0090-subsets-ii
0131-palindrome-partitioning
0254-factor-combinations
0320-generalized-abbreviation
0351-android-unlock-patterns
0465-optimal-account-balancing
0494-target-sum
0865-robot-room-cleaner
1715-split-a-string-into-the-max-number-of-unique-substrings
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2456-construct-smallest-number-from-di-string
2823-the-knights-tour
3780-permutations-iii

Bit Manipulation

0078-subsets
0090-subsets-ii
0187-repeated-dna-sequences
0190-reverse-bits
0266-palindrome-permutation
0268-missing-number
0320-generalized-abbreviation
0338-counting-bits
0351-android-unlock-patterns
0421-maximum-xor-of-two-numbers-in-an-array
0465-optimal-account-balancing
0476-number-complement
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2308-divide-array-into-equal-pairs
2323-minimum-bit-flips-to-convert-number
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
3307-find-the-maximum-sum-of-node-values
3348-minimum-cost-walk-in-weighted-graph
3394-minimum-array-end
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Sorting

0018-4sum
0049-group-anagrams
0056-merge-intervals
0088-merge-sorted-array
0179-largest-number
0268-missing-number
0274-h-index
0314-binary-tree-vertical-order-traversal
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0360-sort-transformed-array
0414-third-maximum-number
0539-minimum-time-difference
0658-find-k-closest-elements
0719-find-k-th-smallest-pair-distance
0721-accounts-merge
0726-number-of-atoms
0778-reorganize-string
1029-vertical-order-traversal-of-a-binary-tree
1074-high-five
1085-the-earliest-moment-when-everyone-become-friends
1098-largest-unique-number
1108-analyze-user-website-visit-pattern
1165-meeting-scheduler
1256-rank-transform-of-an-array
1333-sort-the-jumbled-numbers
1352-maximum-profit-in-job-scheduling
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1741-sort-array-by-increasing-frequency
1829-maximum-units-on-a-truck
1966-frequency-of-the-most-frequent-element
2160-minimum-operations-to-make-a-uni-value-grid
2180-maximum-number-of-tasks-you-can-assign
2331-intersection-of-multiple-arrays
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2502-sort-the-people
2506-minimize-maximum-value-in-a-grid
2581-divide-players-into-teams-of-equal-skill
2588-maximum-number-of-points-from-grid-queries
2640-maximum-number-of-integers-to-choose-from-a-range-i
2681-put-marbles-in-bags
2699-count-the-number-of-fair-pairs
2756-buy-two-chocolates
2846-robot-collisions
2888-minimum-index-of-a-valid-split
3001-apply-operations-to-maximize-score
3276-minimum-number-of-pushes-to-type-word-ii
3307-find-the-maximum-sum-of-node-values
3474-better-compression-of-string
3504-minimum-moves-to-get-a-peaceful-board

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0179-largest-number
0605-can-place-flowers
0624-maximum-distance-in-arrays
0678-valid-parenthesis-string
0680-valid-palindrome-ii
0768-partition-labels
0778-reorganize-string
0797-rabbits-in-forest
0890-lemonade-change
0957-minimum-add-to-make-parentheses-valid
0979-di-string-match
1051-shortest-way-to-form-string
1252-break-a-palindrome
1329-minimum-cost-to-move-chips-to-the-same-position
1502-construct-k-palindrome-strings
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1766-minimum-number-of-removals-to-make-mountain-array
1818-maximum-score-from-removing-substrings
1829-maximum-units-on-a-truck
1966-frequency-of-the-most-frequent-element
2088-minimum-time-to-type-word-using-special-typewriter
2089-maximum-matrix-sum
2095-minimum-number-of-swaps-to-make-the-string-balanced
2180-maximum-number-of-tasks-you-can-assign
2354-minimum-health-to-beat-game
2456-construct-smallest-number-from-di-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2640-maximum-number-of-integers-to-choose-from-a-range-i
2674-make-the-prefix-sum-non-negative
2681-put-marbles-in-bags
2756-buy-two-chocolates
3001-apply-operations-to-maximize-score
3081-minimum-array-length-after-pair-removals
3276-minimum-number-of-pushes-to-type-word-ii
3307-find-the-maximum-sum-of-node-values
3445-lexicographically-minimum-string-after-removing-stars
3504-minimum-moves-to-get-a-peaceful-board

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0008-string-to-integer-atoi
0012-integer-to-roman
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0032-longest-valid-parentheses
0038-count-and-say
0049-group-anagrams
0072-edit-distance
0079-word-search
0091-decode-ways
0097-interleaving-string
0115-distinct-subsequences
0127-word-ladder
0131-palindrome-partitioning
0139-word-break
0166-fraction-to-recurring-decimal
0171-excel-sheet-column-number
0179-largest-number
0187-repeated-dna-sequences
0205-isomorphic-strings
0211-design-add-and-search-words-data-structure
0214-shortest-palindrome
0227-basic-calculator-ii
0241-different-ways-to-add-parentheses
0243-shortest-word-distance
0244-shortest-word-distance-ii
0266-palindrome-permutation
0269-alien-dictionary
0273-integer-to-english-words
0290-word-pattern
0297-serialize-and-deserialize-binary-tree
0320-generalized-abbreviation
0387-first-unique-character-in-a-string
0408-valid-word-abbreviation
0433-minimum-genetic-mutation
0443-string-compression
0472-concatenated-words
0500-keyboard-row
0516-longest-palindromic-subsequence
0539-minimum-time-difference
0564-find-the-closest-palindrome
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0664-strange-printer
0678-valid-parenthesis-string
0680-valid-palindrome-ii
0721-accounts-merge
0726-number-of-atoms
0768-partition-labels
0778-reorganize-string
0812-rotate-string
0868-push-dominoes
0874-backspace-string-compare
0920-uncommon-words-from-two-sentences
0952-word-subsets
0957-minimum-add-to-make-parentheses-valid
0979-di-string-match
1023-time-based-key-value-store
1051-shortest-way-to-form-string
1058-lexicographically-smallest-equivalent-string
1060-longest-repeating-substring
1084-find-k-length-substrings-with-no-repeated-characters
1093-recover-a-tree-from-preorder-traversal
1119-robot-bounded-in-circle
1170-shortest-common-supersequence
1190-smallest-common-region
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1252-break-a-palindrome
1283-reformat-date
1298-reverse-substrings-between-each-pair-of-parentheses
1302-delete-characters-to-make-fancy-string
1320-remove-all-adjacent-duplicates-in-string-ii
1345-perform-string-shifts
1350-remove-sub-folders-from-the-filesystem
1371-minimum-remove-to-make-valid-parentheses
1473-find-the-longest-substring-containing-vowels-in-even-counts
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1667-find-kth-bit-in-nth-binary-string
1715-split-a-string-into-the-max-number-of-unique-substrings
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
1786-count-the-number-of-consistent-strings
1818-maximum-score-from-removing-substrings
1894-merge-strings-alternately
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
1923-sentence-similarity-iii
2021-remove-all-occurrences-of-a-substring
2076-sum-of-digits-of-string-after-convert
2079-delete-duplicate-folders-in-system
2088-minimum-time-to-type-word-using-special-typewriter
2095-minimum-number-of-swaps-to-make-the-string-balanced
2163-kth-distinct-string-in-an-array
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2220-find-all-possible-recipes-from-given-supplies
2243-check-if-all-as-appears-before-all-bs
2292-counting-words-with-a-given-prefix
2303-unique-substrings-with-equal-digit-frequency
2456-construct-smallest-number-from-di-string
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2494-sum-of-prefix-scores-of-strings
2502-sort-the-people
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2580-circular-sentence
2599-take-k-of-each-character-from-left-and-right
2691-count-vowel-strings-in-ranges
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
3194-find-words-containing-character
3235-minimum-cost-to-convert-string-i
3243-count-the-number-of-powerful-integers
3247-number-of-same-end-substrings
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3451-string-compression-iii
3474-better-compression-of-string
3567-convert-date-to-binary
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3753-maximum-difference-between-even-and-odd-frequency-i
3931-process-string-with-special-operations-i

Matrix

0036-valid-sudoku
0059-spiral-matrix-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0079-word-search
0200-number-of-islands
0221-maximal-square
0286-walls-and-gates
0302-smallest-rectangle-enclosing-black-pixels
0311-sparse-matrix-multiplication
0317-shortest-distance-from-all-buildings
0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0419-battleships-in-a-board
0566-reshape-the-matrix
0695-max-area-of-island
0854-making-a-large-island
0921-spiral-matrix-iii
0999-regions-cut-by-slashes
1036-rotting-oranges
1147-flip-columns-for-maximum-number-of-equal-rows
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1496-lucky-numbers-in-a-matrix
1691-minimum-number-of-days-to-disconnect-island
1972-rotating-the-box
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2160-minimum-operations-to-make-a-uni-value-grid
2506-minimize-maximum-value-in-a-grid
2588-maximum-number-of-points-from-grid-queries
2685-first-completely-painted-row-or-column
2823-the-knights-tour
3227-find-missing-and-repeated-values
3526-minimum-number-of-flips-to-make-binary-grid-palindromic-i

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0055-jump-game
0062-unique-paths
0064-minimum-path-sum
0072-edit-distance
0091-decode-ways
0097-interleaving-string
0115-distinct-subsequences
0118-pascals-triangle
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0131-palindrome-partitioning
0139-word-break
0152-maximum-product-subarray
0198-house-robber
0221-maximal-square
0241-different-ways-to-add-parentheses
0256-paint-house
0264-ugly-number-ii
0265-paint-house-ii
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0338-counting-bits
0351-android-unlock-patterns
0416-partition-equal-subset-sum
0465-optimal-account-balancing
0472-concatenated-words
0487-max-consecutive-ones-ii
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0650-2-keys-keyboard
0664-strange-printer
0678-valid-parenthesis-string
0803-cheapest-flights-within-k-stops
0806-domino-and-tromino-tiling
0868-push-dominoes
0905-length-of-longest-fibonacci-subsequence
1060-longest-repeating-substring
1166-toss-strange-coins
1170-shortest-common-supersequence
1196-filling-bookcase-shelves
1240-stone-game-ii
1250-longest-common-subsequence
1352-maximum-profit-in-job-scheduling
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1511-count-number-of-teams
1631-number-of-sub-arrays-with-odd-sum
1756-minimum-deletions-to-make-string-balanced
1766-minimum-number-of-removals-to-make-mountain-array
1849-maximum-absolute-sum-of-any-subarray
2028-the-earliest-and-latest-rounds-where-players-compete
2067-maximum-number-of-points-with-cost
2090-number-of-ways-to-arrive-at-destination
2262-solving-questions-with-brainpower
2415-count-the-number-of-ideal-arrays
2755-extra-characters-in-a-string
3243-count-the-number-of-powerful-integers
3307-find-the-maximum-sum-of-node-values
3949-minimum-number-of-primes-to-sum-to-target

Simulation

0059-spiral-matrix-ii
0566-reshape-the-matrix
0592-fraction-addition-and-subtraction
0735-asteroid-collision
0874-backspace-string-compare
0906-walking-robot-simulation
0921-spiral-matrix-iii
1119-robot-bounded-in-circle
1667-find-kth-bit-in-nth-binary-string
1803-average-waiting-time
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2021-remove-all-occurrences-of-a-substring
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2169-simple-bank-system
2265-partition-array-according-to-given-pivot
2299-merge-nodes-in-between-zeros
2324-find-triangular-sum-of-an-array
2479-meeting-rooms-iii
2551-apply-operations-to-an-array
2645-pass-the-pillow
2692-take-gifts-from-the-richest-pile
2846-robot-collisions
3434-find-the-number-of-distinct-colors-among-the-balls
3447-clear-digits
3931-process-string-with-special-operations-i

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0050-powx-n
0062-unique-paths
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0166-fraction-to-recurring-decimal
0171-excel-sheet-column-number
0202-happy-number
0204-count-primes
0227-basic-calculator-ii
0241-different-ways-to-add-parentheses
0263-ugly-number
0264-ugly-number-ii
0268-missing-number
0273-integer-to-english-words
0319-bulb-switcher
0360-sort-transformed-array
0380-insert-delete-getrandom-o1
0398-random-pick-index
0539-minimum-time-difference
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0650-2-keys-keyboard
0796-reaching-points
0797-rabbits-in-forest
0866-rectangle-overlap
0903-implement-rand10-using-rand7
0912-random-pick-with-weight
1119-robot-bounded-in-circle
1166-toss-strange-coins
1240-stone-game-ii
1329-minimum-cost-to-move-chips-to-the-same-position
1345-perform-string-shifts
1411-convert-binary-number-in-a-linked-list-to-integer
1477-product-of-the-last-k-numbers
1500-count-largest-group
1631-number-of-sub-arrays-with-odd-sum
1693-sum-of-all-odd-length-subarrays
1774-add-two-polynomials-represented-as-linked-lists
1889-check-if-number-is-a-sum-of-powers-of-three
1951-find-the-winner-of-the-circular-game
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2155-find-missing-observations
2160-minimum-operations-to-make-a-uni-value-grid
2324-find-triangular-sum-of-an-array
2415-count-the-number-of-ideal-arrays
2448-count-number-of-bad-pairs
2610-closest-prime-numbers-in-range
2645-pass-the-pillow
2649-count-total-number-of-colored-cells
2903-insert-greatest-common-divisors-in-linked-list
3001-apply-operations-to-maximize-score
3172-divisible-and-non-divisible-sums-difference
3216-distribute-candies-among-children-iii
3227-find-missing-and-repeated-values
3243-count-the-number-of-powerful-integers
3548-find-the-count-of-good-integers
3567-convert-date-to-binary
3606-minimum-element-after-replacement-with-digit-sum
3817-maximum-containers-on-a-ship
3949-minimum-number-of-primes-to-sum-to-target

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0341-flatten-nested-list-iterator
0362-design-hit-counter
0387-first-unique-character-in-a-string
0859-design-circular-deque
0892-shortest-subarray-with-sum-at-least-k
0969-number-of-recent-calls
1366-first-unique-number
1951-find-the-winner-of-the-circular-game
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds
2868-continuous-subarrays
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0227-basic-calculator-ii
0232-implement-queue-using-stacks
0255-verify-preorder-sequence-in-binary-search-tree
0272-closest-binary-search-tree-value-ii
0341-flatten-nested-list-iterator
0364-nested-list-weight-sum-ii
0496-next-greater-element-i
0636-exclusive-time-of-functions
0678-valid-parenthesis-string
0716-max-stack
0726-number-of-atoms
0735-asteroid-collision
0758-convert-binary-search-tree-to-sorted-doubly-linked-list
0775-n-ary-tree-preorder-traversal
0776-n-ary-tree-postorder-traversal
0874-backspace-string-compare
0957-minimum-add-to-make-parentheses-valid
1197-parsing-a-boolean-expression
1298-reverse-substrings-between-each-pair-of-parentheses
1320-remove-all-adjacent-duplicates-in-string-ii
1371-minimum-remove-to-make-valid-parentheses
1497-design-a-stack-with-increment-operation
1582-design-browser-history
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1720-crawler-log-folder
1756-minimum-deletions-to-make-string-balanced
1818-maximum-score-from-removing-substrings
1903-design-most-recently-used-queue
2021-remove-all-occurrences-of-a-substring
2095-minimum-number-of-swaps-to-make-the-string-balanced
2456-construct-smallest-number-from-di-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2846-robot-collisions
3001-apply-operations-to-maximize-score
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals
2324-find-triangular-sum-of-an-array
2415-count-the-number-of-ideal-arrays
3216-distribute-candies-among-children-iii
3548-find-the-count-of-good-integers

Trie

0139-word-break
0211-design-add-and-search-words-data-structure
0386-lexicographical-numbers
0421-maximum-xor-of-two-numbers-in-an-array
0440-k-th-smallest-in-lexicographical-order
0472-concatenated-words
1350-remove-sub-folders-from-the-filesystem
2009-longest-word-with-all-prefixes
2079-delete-duplicate-folders-in-system
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix

Memoization

0139-word-break
0241-different-ways-to-add-parentheses
2028-the-earliest-and-latest-rounds-where-players-compete

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0190-reverse-bits
0347-top-k-frequent-elements
0925-construct-binary-tree-from-preorder-and-postorder-traversal
2280-count-good-triplets-in-an-array

Heap (Priority Queue)

0023-merge-k-sorted-lists
0264-ugly-number-ii
0272-closest-binary-search-tree-value-ii
0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
0407-trapping-rain-water-ii
0658-find-k-closest-elements
0744-network-delay-time
0778-reorganize-string
0789-kth-largest-element-in-a-stream
0803-cheapest-flights-within-k-stops
0892-shortest-subarray-with-sum-at-least-k
1074-high-five
1325-path-with-maximum-probability
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2012-process-tasks-using-servers
2230-minimum-cost-to-reach-city-with-discounts
2434-design-a-number-container-system
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2588-maximum-number-of-points-from-grid-queries
2674-make-the-prefix-sum-non-negative
2681-put-marbles-in-bags
2692-take-gifts-from-the-richest-pile
2868-continuous-subarrays
2880-find-the-closest-marked-node
3445-lexicographically-minimum-string-after-removing-stars

Shortest Path

0744-network-delay-time
0803-cheapest-flights-within-k-stops
1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2090-number-of-ways-to-arrive-at-destination
2171-second-minimum-time-to-reach-destination
2230-minimum-cost-to-reach-city-with-discounts
2880-find-the-closest-marked-node
3235-minimum-cost-to-convert-string-i

Design

0146-lru-cache
0173-binary-search-tree-iterator
0211-design-add-and-search-words-data-structure
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0244-shortest-word-distance-ii
0251-flatten-2d-vector
0297-serialize-and-deserialize-binary-tree
0341-flatten-nested-list-iterator
0359-logger-rate-limiter
0362-design-hit-counter
0380-insert-delete-getrandom-o1
0432-all-oone-data-structure
0460-lfu-cache
0716-max-stack
0729-my-calendar-i
0731-my-calendar-ii
0789-kth-largest-element-in-a-stream
0816-design-hashset
0817-design-hashmap
0859-design-circular-deque
0969-number-of-recent-calls
1023-time-based-key-value-store
1366-first-unique-number
1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
1497-design-a-stack-with-increment-operation
1582-design-browser-history
1903-design-most-recently-used-queue
1905-design-authentication-manager
2169-simple-bank-system
2434-design-a-number-container-system

Binary Indexed Tree

1511-count-number-of-teams
1903-design-most-recently-used-queue
2280-count-good-triplets-in-an-array

Probability and Statistics

0903-implement-rand10-using-rand7
1166-toss-strange-coins

Sliding Window

0003-longest-substring-without-repeating-characters
0187-repeated-dna-sequences
0487-max-consecutive-ones-ii
0567-permutation-in-string
0658-find-k-closest-elements
0892-shortest-subarray-with-sum-at-least-k
1046-max-consecutive-ones-iii
1084-find-k-length-substrings-with-no-repeated-characters
1107-minimum-swaps-to-group-all-1s-together
1755-defuse-the-bomb
1966-frequency-of-the-most-frequent-element
2003-distinct-numbers-in-each-subarray
2247-number-of-unique-flavors-after-sharing-k-candies
2255-minimum-swaps-to-group-all-1s-together-ii
2394-count-subarrays-with-score-less-than-k
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2527-count-subarrays-with-fixed-bounds
2599-take-k-of-each-character-from-left-and-right
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
2868-continuous-subarrays
3213-count-subarrays-where-max-element-appears-at-least-k-times
3267-find-longest-special-substring-that-occurs-thrice-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3522-find-the-power-of-k-size-subarrays-i
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii

Prefix Sum

0238-product-of-array-except-self
0325-maximum-size-subarray-sum-equals-k
0560-subarray-sum-equals-k
0731-my-calendar-ii
0892-shortest-subarray-with-sum-at-least-k
0912-random-pick-with-weight
1046-max-consecutive-ones-iii
1240-stone-game-ii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1477-product-of-the-last-k-numbers
1514-minimum-value-to-get-positive-step-by-step-sum
1537-maximum-score-after-splitting-a-string
1631-number-of-sub-arrays-with-odd-sum
1693-sum-of-all-odd-length-subarrays
1694-make-sum-divisible-by-p
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1966-frequency-of-the-most-frequent-element
2006-find-the-student-that-will-replace-the-chalk
2249-count-the-hidden-sequences
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
2915-count-of-interesting-subarrays
3247-number-of-same-end-substrings
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Rolling Hash

0187-repeated-dna-sequences
0214-shortest-palindrome
1060-longest-repeating-substring
2303-unique-substrings-with-equal-digit-frequency
3309-count-prefix-and-suffix-pairs-i

Suffix Array

1060-longest-repeating-substring

Hash Function

0187-repeated-dna-sequences
0214-shortest-palindrome
0572-subtree-of-another-tree
0816-design-hashset
0817-design-hashmap
1060-longest-repeating-substring
2079-delete-duplicate-folders-in-system
2303-unique-substrings-with-equal-digit-frequency
3309-count-prefix-and-suffix-pairs-i

Counting

0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0778-reorganize-string
0920-uncommon-words-from-two-sentences
1055-pairs-of-songs-with-total-durations-divisible-by-60
1149-intersection-of-three-sorted-arrays
1227-number-of-equivalent-domino-pairs
1502-construct-k-palindrome-strings
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
1915-check-if-one-string-swap-can-make-strings-equal
2163-kth-distinct-string-in-an-array
2303-unique-substrings-with-equal-digit-frequency
2308-divide-array-into-equal-pairs
2331-intersection-of-multiple-arrays
2448-count-number-of-bad-pairs
2494-sum-of-prefix-scores-of-strings
2614-maximum-count-of-positive-integer-and-negative-integer
3081-minimum-array-length-after-pair-removals
3247-number-of-same-end-substrings
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3474-better-compression-of-string
3519-find-the-number-of-winning-players
3594-identify-the-largest-outlier-in-an-array
3753-maximum-difference-between-even-and-odd-frequency-i

Merge Sort

0023-merge-k-sorted-lists
2280-count-good-triplets-in-an-array

Bitmask

0351-android-unlock-patterns
0465-optimal-account-balancing

Strongly Connected Component

1691-minimum-number-of-days-to-disconnect-island

Counting Sort

0274-h-index
3504-minimum-moves-to-get-a-peaceful-board

Data Stream

0359-logger-rate-limiter
0362-design-hit-counter
0789-kth-largest-element-in-a-stream
0969-number-of-recent-calls
1366-first-unique-number
1477-product-of-the-last-k-numbers
1582-design-browser-history

Game Theory

1240-stone-game-ii

Geometry

0149-max-points-on-a-line
0866-rectangle-overlap

Randomized

0380-insert-delete-getrandom-o1
0398-random-pick-index
0903-implement-rand10-using-rand7
0912-random-pick-with-weight

Eulerian Circuit

0332-reconstruct-itinerary

Number Theory

0204-count-primes
2415-count-the-number-of-ideal-arrays
2610-closest-prime-numbers-in-range
2903-insert-greatest-common-divisors-in-linked-list
3001-apply-operations-to-maximize-score
3949-minimum-number-of-primes-to-sum-to-target

Brainteaser

0319-bulb-switcher
2503-longest-subarray-with-maximum-bitwise-and

Iterator

0173-binary-search-tree-iterator
0251-flatten-2d-vector
0341-flatten-nested-list-iterator

String Matching

0214-shortest-palindrome
0572-subtree-of-another-tree
0812-rotate-string
1524-string-matching-in-an-array
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Segment Tree

0729-my-calendar-i
0731-my-calendar-ii
2280-count-good-triplets-in-an-array

Ordered Set

0716-max-stack
0729-my-calendar-i
0731-my-calendar-ii
1903-design-most-recently-used-queue
2280-count-good-triplets-in-an-array
2434-design-a-number-container-system
2868-continuous-subarrays

Interactive

0277-find-the-celebrity
0865-robot-room-cleaner

Monotonic Stack

0042-trapping-rain-water
0255-verify-preorder-sequence-in-binary-search-tree
0496-next-greater-element-i
1679-shortest-subarray-to-be-removed-to-make-array-sorted
3001-apply-operations-to-maximize-score

Monotonic Queue

0892-shortest-subarray-with-sum-at-least-k
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds
2868-continuous-subarrays

Reservoir Sampling

0398-random-pick-index

Enumeration

0204-count-primes
1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
3548-find-the-count-of-good-integers
3594-identify-the-largest-outlier-in-an-array

Database

0197-rising-temperature
0577-employee-bonus
1153-product-sales-analysis-i
1415-students-and-examinations
1509-replace-employee-id-with-the-unique-identifier
1724-customer-who-visited-but-did-not-make-any-transactions
1801-average-time-of-process-per-machine
2087-confirmation-rate

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Rejection Sampling

0903-implement-rand10-using-rand7

Minimum Spanning Tree

1706-min-cost-to-connect-all-points