LeetCode Topics

Array

0033-search-in-rotated-sorted-array
0045-jump-game-ii
0046-permutations
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0055-jump-game
0136-single-number
0162-find-peak-element
0228-summary-ranges
0253-meeting-rooms-ii
0287-find-the-duplicate-number
0376-wiggle-subsequence
0455-assign-cookies
0542-01-matrix
0550-shortest-path-to-get-food
0630-course-schedule-iii
0646-maximum-length-of-pair-chain
0761-employee-free-time
1014-k-closest-points-to-origin
1019-squares-of-a-sorted-array
1112-find-words-that-can-be-formed-by-characters
1149-intersection-of-three-sorted-arrays
1476-count-negative-numbers-in-a-sorted-matrix
1482-how-many-numbers-are-smaller-than-the-current-number
1483-rank-teams-by-votes
1547-destination-city
1802-number-of-students-unable-to-eat-lunch
1927-maximum-ascending-subarray-sum
2107-find-unique-binary-string
2210-find-target-indices-after-sorting-array
2219-maximum-number-of-words-found-in-sentences
2308-divide-array-into-equal-pairs
2589-maximum-value-of-a-string-in-an-array
2668-form-smallest-number-from-two-digit-arrays
2881-split-strings-by-separator
3221-find-the-peaks
3242-count-elements-with-maximum-frequency
3309-count-prefix-and-suffix-pairs-i
3332-minimum-operations-to-exceed-threshold-value-ii
3397-find-the-integer-added-to-array-i
3501-delete-nodes-from-linked-list-present-in-array
3708-zigzag-grid-traversal-with-skip

Binary Search

0033-search-in-rotated-sorted-array
0162-find-peak-element
0270-closest-binary-search-tree-value
0287-find-the-duplicate-number
1149-intersection-of-three-sorted-arrays
1476-count-negative-numbers-in-a-sorted-matrix
2210-find-target-indices-after-sorting-array

Matrix

0048-rotate-image
0542-01-matrix
0550-shortest-path-to-get-food
1476-count-negative-numbers-in-a-sorted-matrix
3708-zigzag-grid-traversal-with-skip

Hash Table

0003-longest-substring-without-repeating-characters
0049-group-anagrams
0133-clone-graph
0141-linked-list-cycle
0387-first-unique-character-in-a-string
0653-two-sum-iv-input-is-a-bst
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1112-find-words-that-can-be-formed-by-characters
1149-intersection-of-three-sorted-arrays
1482-how-many-numbers-are-smaller-than-the-current-number
1483-rank-teams-by-votes
1547-destination-city
2053-check-if-all-characters-have-equal-number-of-occurrences
2107-find-unique-binary-string
2308-divide-array-into-equal-pairs
2668-form-smallest-number-from-two-digit-arrays
3242-count-elements-with-maximum-frequency
3501-delete-nodes-from-linked-list-present-in-array
3753-maximum-difference-between-even-and-odd-frequency-i

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0008-string-to-integer-atoi
0049-group-anagrams
0067-add-binary
0301-remove-invalid-parentheses
0387-first-unique-character-in-a-string
0606-construct-string-from-binary-tree
0851-goat-latin
1112-find-words-that-can-be-formed-by-characters
1483-rank-teams-by-votes
1547-destination-city
1894-merge-strings-alternately
2053-check-if-all-characters-have-equal-number-of-occurrences
2076-sum-of-digits-of-string-after-convert
2107-find-unique-binary-string
2168-check-if-numbers-are-ascending-in-a-sentence
2217-step-by-step-directions-from-a-binary-tree-node-to-another
2219-maximum-number-of-words-found-in-sentences
2589-maximum-value-of-a-string-in-an-array
2881-split-strings-by-separator
3309-count-prefix-and-suffix-pairs-i
3753-maximum-difference-between-even-and-odd-frequency-i

Sorting

0049-group-anagrams
0253-meeting-rooms-ii
0455-assign-cookies
0630-course-schedule-iii
0646-maximum-length-of-pair-chain
0761-employee-free-time
1014-k-closest-points-to-origin
1019-squares-of-a-sorted-array
1482-how-many-numbers-are-smaller-than-the-current-number
1483-rank-teams-by-votes
2210-find-target-indices-after-sorting-array

Dynamic Programming

0005-longest-palindromic-substring
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0096-unique-binary-search-trees
0376-wiggle-subsequence
0542-01-matrix
0646-maximum-length-of-pair-chain

Greedy

0045-jump-game-ii
0055-jump-game
0253-meeting-rooms-ii
0376-wiggle-subsequence
0455-assign-cookies
0630-course-schedule-iii
0646-maximum-length-of-pair-chain

Math

0048-rotate-image
0067-add-binary
0096-unique-binary-search-trees
1014-k-closest-points-to-origin

Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0103-binary-tree-zigzag-level-order-traversal
0199-binary-tree-right-side-view
0235-lowest-common-ancestor-of-a-binary-search-tree
0270-closest-binary-search-tree-value
0606-construct-string-from-binary-tree
0653-two-sum-iv-input-is-a-bst
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1254-deepest-leaves-sum
1484-linked-list-in-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another

Binary Search Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0270-closest-binary-search-tree-value
0653-two-sum-iv-input-is-a-bst

Binary Tree

0096-unique-binary-search-trees
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0103-binary-tree-zigzag-level-order-traversal
0199-binary-tree-right-side-view
0235-lowest-common-ancestor-of-a-binary-search-tree
0270-closest-binary-search-tree-value
0606-construct-string-from-binary-tree
0653-two-sum-iv-input-is-a-bst
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1254-deepest-leaves-sum
1484-linked-list-in-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another

Depth-First Search

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0133-clone-graph
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0235-lowest-common-ancestor-of-a-binary-search-tree
0270-closest-binary-search-tree-value
0606-construct-string-from-binary-tree
0653-two-sum-iv-input-is-a-bst
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1254-deepest-leaves-sum
1484-linked-list-in-binary-tree
1558-course-schedule-iv
2121-find-if-path-exists-in-graph
2217-step-by-step-directions-from-a-binary-tree-node-to-another

Breadth-First Search

0103-binary-tree-zigzag-level-order-traversal
0133-clone-graph
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0301-remove-invalid-parentheses
0542-01-matrix
0550-shortest-path-to-get-food
0653-two-sum-iv-input-is-a-bst
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1254-deepest-leaves-sum
1558-course-schedule-iv
2121-find-if-path-exists-in-graph

Two Pointers

0005-longest-palindromic-substring
0141-linked-list-cycle
0253-meeting-rooms-ii
0287-find-the-duplicate-number
0455-assign-cookies
0528-swapping-nodes-in-a-linked-list
0653-two-sum-iv-input-is-a-bst
1019-squares-of-a-sorted-array
1894-merge-strings-alternately

Bit Manipulation

0067-add-binary
0136-single-number
0287-find-the-duplicate-number
2308-divide-array-into-equal-pairs

Simulation

0067-add-binary
1802-number-of-students-unable-to-eat-lunch
2076-sum-of-digits-of-string-after-convert
3332-minimum-operations-to-exceed-threshold-value-ii
3708-zigzag-grid-traversal-with-skip

Union Find

2121-find-if-path-exists-in-graph

Graph

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
1558-course-schedule-iv
2121-find-if-path-exists-in-graph

Queue

0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string
0969-number-of-recent-calls
1802-number-of-students-unable-to-eat-lunch

Counting

0387-first-unique-character-in-a-string
1112-find-words-that-can-be-formed-by-characters
1149-intersection-of-three-sorted-arrays
1482-how-many-numbers-are-smaller-than-the-current-number
1483-rank-teams-by-votes
2053-check-if-all-characters-have-equal-number-of-occurrences
2308-divide-array-into-equal-pairs
3242-count-elements-with-maximum-frequency
3753-maximum-difference-between-even-and-odd-frequency-i

Design

0232-implement-queue-using-stacks
0969-number-of-recent-calls

Data Stream

0969-number-of-recent-calls

Stack

0232-implement-queue-using-stacks
1802-number-of-students-unable-to-eat-lunch

Heap (Priority Queue)

0253-meeting-rooms-ii
0630-course-schedule-iii
0761-employee-free-time
1014-k-closest-points-to-origin
3332-minimum-operations-to-exceed-threshold-value-ii

Prefix Sum

0253-meeting-rooms-ii

Topological Sort

0207-course-schedule
0210-course-schedule-ii
1558-course-schedule-iv

Divide and Conquer

0053-maximum-subarray
1014-k-closest-points-to-origin

Geometry

1014-k-closest-points-to-origin

Quickselect

1014-k-closest-points-to-origin

Linked List

0141-linked-list-cycle
0528-swapping-nodes-in-a-linked-list
1484-linked-list-in-binary-tree
1765-merge-in-between-linked-lists
3501-delete-nodes-from-linked-list-present-in-array

Sliding Window

0003-longest-substring-without-repeating-characters

Backtracking

0046-permutations
0301-remove-invalid-parentheses
2107-find-unique-binary-string

Enumeration

2668-form-smallest-number-from-two-digit-arrays
3221-find-the-peaks

Trie

3309-count-prefix-and-suffix-pairs-i

Rolling Hash

3309-count-prefix-and-suffix-pairs-i

String Matching

3309-count-prefix-and-suffix-pairs-i

Hash Function

3309-count-prefix-and-suffix-pairs-i

Database

1948-rearrange-products-table