LeetCode Solutions 📝

This repository contains my solutions to various problems from LeetCode. 📚

Easy - Medium - Hard 🟢-🟡-🔴

Author 👤

My Leetcode Prifile Link - https://leetcode.com/surajit2003/

Contents 📖

• Array 📊
• Strings 🔤
• Linked List ⛓️
• Trees 🌳
• Graphs 🌐
• Dynamic Programming 📈
• Stack 🚦
• Queues ➡️
• Greedy 💰
• Recursion 🔁

LeetCode Topics

Database

0586-customer-placing-the-largest-number-of-orders
1541-top-travellers

Array

0001-two-sum
0015-3sum
0016-3sum-closest
0026-remove-duplicates-from-sorted-array
0054-spiral-matrix
0055-jump-game
0073-set-matrix-zeroes
0075-sort-colors
0079-word-search
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0136-single-number
0189-rotate-array
0198-house-robber
0209-minimum-size-subarray-sum
0213-house-robber-ii
0268-missing-number
0283-move-zeroes
0289-game-of-life
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0453-minimum-moves-to-equal-array-elements
0485-max-consecutive-ones
0496-next-greater-element-i
0713-subarray-product-less-than-k
0747-min-cost-climbing-stairs
0890-lemonade-change
1016-subarray-sums-divisible-by-k
1293-three-consecutive-odds
1519-minimum-subsequence-in-non-increasing-order
1538-maximum-points-you-can-obtain-from-cards
2106-find-greatest-common-divisor-of-array
2714-left-and-right-sum-differences
3235-minimum-cost-to-convert-string-i

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0073-set-matrix-zeroes
0133-clone-graph
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0202-happy-number
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0387-first-unique-character-in-a-string
0496-next-greater-element-i
1016-subarray-sums-divisible-by-k

Two Pointers

0015-3sum
0016-3sum-closest
0026-remove-duplicates-from-sorted-array
0028-find-the-index-of-the-first-occurrence-in-a-string
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0086-partition-list
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0345-reverse-vowels-of-a-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0680-valid-palindrome-ii
0908-middle-of-the-linked-list

Binary Search

0069-sqrtx
0209-minimum-size-subarray-sum
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0441-arranging-coins

Sorting

0015-3sum
0016-3sum-closest
0075-sort-colors
0088-merge-sorted-array
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
1519-minimum-subsequence-in-non-increasing-order
2379-maximum-total-importance-of-roads

Dynamic Programming

0022-generate-parentheses
0055-jump-game
0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0198-house-robber
0213-house-robber-ii
0337-house-robber-iii
0747-min-cost-climbing-stairs
1013-fibonacci-number

Tree

0337-house-robber-iii
0437-path-sum-iii

Depth-First Search

0133-clone-graph
0337-house-robber-iii
0437-path-sum-iii
0766-flatten-a-multilevel-doubly-linked-list

Binary Tree

0337-house-robber-iii
0437-path-sum-iii

Math

0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0069-sqrtx
0070-climbing-stairs
0189-rotate-array
0202-happy-number
0258-add-digits
0268-missing-number
0441-arranging-coins
0453-minimum-moves-to-equal-array-elements
1013-fibonacci-number
1411-convert-binary-number-in-a-linked-list-to-integer
2106-find-greatest-common-divisor-of-array
2645-pass-the-pillow

Simulation

0054-spiral-matrix
0258-add-digits
0289-game-of-life
2470-removing-stars-from-a-string
2645-pass-the-pillow

Breadth-First Search

0133-clone-graph

Graph

0133-clone-graph
2379-maximum-total-importance-of-roads
3235-minimum-cost-to-convert-string-i

Greedy

0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0680-valid-palindrome-ii
0890-lemonade-change
1519-minimum-subsequence-in-non-increasing-order
2379-maximum-total-importance-of-roads

Heap (Priority Queue)

0023-merge-k-sorted-lists
2379-maximum-total-importance-of-roads

Matrix

0054-spiral-matrix
0073-set-matrix-zeroes
0079-word-search
0289-game-of-life

Prefix Sum

0209-minimum-size-subarray-sum
1016-subarray-sums-divisible-by-k
1538-maximum-points-you-can-obtain-from-cards
2714-left-and-right-sum-differences

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0713-subarray-product-less-than-k
1538-maximum-points-you-can-obtain-from-cards

String

0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0079-word-search
0125-valid-palindrome
0151-reverse-words-in-a-string
0242-valid-anagram
0345-reverse-vowels-of-a-string
0387-first-unique-character-in-a-string
0680-valid-palindrome-ii
2470-removing-stars-from-a-string
3235-minimum-cost-to-convert-string-i

Backtracking

0022-generate-parentheses
0079-word-search

Stack

0020-valid-parentheses
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0496-next-greater-element-i
2470-removing-stars-from-a-string

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string

Trie

0014-longest-common-prefix

Shortest Path

3235-minimum-cost-to-convert-string-i

Linked List

0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0083-remove-duplicates-from-sorted-list
0086-partition-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0766-flatten-a-multilevel-doubly-linked-list
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer

Recursion

0021-merge-two-sorted-lists
0206-reverse-linked-list
0234-palindrome-linked-list
1013-fibonacci-number

Doubly-Linked List

0766-flatten-a-multilevel-doubly-linked-list

Divide and Conquer

0023-merge-k-sorted-lists

Merge Sort

0023-merge-k-sorted-lists

Design

0225-implement-stack-using-queues
0232-implement-queue-using-stacks

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0387-first-unique-character-in-a-string

Monotonic Stack

0496-next-greater-element-i

Bit Manipulation

0136-single-number
0268-missing-number

Number Theory

0258-add-digits
2106-find-greatest-common-divisor-of-array

Memoization

0070-climbing-stairs
1013-fibonacci-number

Counting

0387-first-unique-character-in-a-string