LeetCode

Welcome to my LeetCode repository! 🚀 This repo contains solutions to various LeetCode problems that I have solved in my journey of improving problem-solving skills and understanding algorithms and data structures.

Introduction

LeetCode is an excellent platform to practice coding problems that cover a wide range of topics, from basic to advanced algorithms and data structures. This repository serves as my personal collection of solutions to LeetCode problems, where each solution is carefully structured and documented for future reference.

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0034-find-first-and-last-position-of-element-in-sorted-array
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0048-rotate-image
0053-maximum-subarray
0055-jump-game
0057-insert-interval
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0084-largest-rectangle-in-histogram
0090-subsets-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0123-best-time-to-buy-and-sell-stock-iii
0130-surrounded-regions
0135-candy
0136-single-number
0162-find-peak-element
0169-majority-element
0188-best-time-to-buy-and-sell-stock-iv
0189-rotate-array
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0219-contains-duplicate-ii
0229-majority-element-ii
0239-sliding-window-maximum
0283-move-zeroes
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0322-coin-change
0347-top-k-frequent-elements
0368-largest-divisible-subset
0414-third-maximum-number
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0455-assign-cookies
0474-ones-and-zeroes
0485-max-consecutive-ones
0496-next-greater-element-i
0498-diagonal-traverse
0503-next-greater-element-ii
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence
0621-task-scheduler
0643-maximum-average-subarray-i
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0717-1-bit-and-2-bit-characters
0733-flood-fill
0735-asteroid-collision
0759-set-intersection-size-at-least-two
0792-binary-search
0794-swim-in-rising-water
0876-hand-of-straights
0890-lemonade-change
0907-koko-eating-bananas
0943-sum-of-subarray-minimums
0966-binary-subarrays-with-sum
0967-minimum-falling-path-sum
1014-k-closest-points-to-origin
1036-rotting-oranges
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1073-number-of-enclaves
1127-last-stone-weight
1129-longest-string-chain
1171-shortest-path-in-binary-matrix
1353-find-resultant-array-after-removing-anagrams
1370-count-number-of-nice-subarrays
1402-count-square-submatrices-with-all-ones
1408-find-the-smallest-divisor-given-a-threshold
1538-maximum-points-you-can-obtain-from-cards
1586-longest-subarray-of-1s-after-deleting-one-element
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
1669-minimum-cost-to-cut-a-stick
1694-make-sum-divisible-by-p
1753-path-with-minimum-effort
1834-minimum-number-of-people-to-teach
1878-check-if-array-is-sorted-and-rotated
1917-maximum-average-pass-ratio
1966-frequency-of-the-most-frequent-element
2162-partition-array-into-two-arrays-to-minimize-sum-difference
2227-sum-of-subarray-ranges
2233-number-of-smooth-descent-periods-of-a-stock
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2307-replace-non-coprime-numbers-in-array
2392-successful-pairs-of-spells-and-potions
2618-maximize-the-minimum-powered-city
2694-find-the-maximum-divisibility-score
3242-count-elements-with-maximum-frequency
3251-maximum-area-of-longest-diagonal-rectangle
3383-taking-maximum-energy-from-the-mystic-dungeon
3612-adjacent-increasing-subarrays-detection-i
3620-maximum-number-of-distinct-elements-after-operations
3748-sort-matrix-by-diagonals
3819-count-covered-buildings
3864-count-the-number-of-computer-unlocking-permutations
3934-coupon-code-validator

Sliding Window

0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0239-sliding-window-maximum
0567-permutation-in-string
0594-longest-harmonious-subsequence
0643-maximum-average-subarray-i
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1538-maximum-points-you-can-obtain-from-cards
1586-longest-subarray-of-1s-after-deleting-one-element
1966-frequency-of-the-most-frequent-element
2618-maximize-the-minimum-powered-city

Binary Search

0034-find-first-and-last-position-of-element-in-sorted-array
0069-sqrtx
0074-search-a-2d-matrix
0162-find-peak-element
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0300-longest-increasing-subsequence
0540-single-element-in-a-sorted-array
0792-binary-search
0794-swim-in-rising-water
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1408-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
1753-path-with-minimum-effort
1966-frequency-of-the-most-frequent-element
2162-partition-array-into-two-arrays-to-minimize-sum-difference
2392-successful-pairs-of-spells-and-potions
2618-maximize-the-minimum-powered-city

Prefix Sum

0209-minimum-size-subarray-sum
0560-subarray-sum-equals-k
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards
1694-make-sum-divisible-by-p
1966-frequency-of-the-most-frequent-element
2618-maximize-the-minimum-powered-city
3383-taking-maximum-energy-from-the-mystic-dungeon

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0061-rotate-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0148-sort-list
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0328-odd-even-linked-list
0355-design-twitter
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0044-wildcard-matching
0050-powx-n
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
1013-fibonacci-number
1197-parsing-a-boolean-expression
2050-count-good-numbers

Hash Table

0001-two-sum
0017-letter-combinations-of-a-phone-number
0073-set-matrix-zeroes
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0127-word-ladder
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0205-isomorphic-strings
0208-implement-trie-prefix-tree
0219-contains-duplicate-ii
0229-majority-element-ii
0347-top-k-frequent-elements
0355-design-twitter
0451-sort-characters-by-frequency
0496-next-greater-element-i
0560-subarray-sum-equals-k
0567-permutation-in-string
0594-longest-harmonious-subsequence
0621-task-scheduler
0876-hand-of-straights
0893-all-nodes-distance-k-in-binary-tree
0966-binary-subarrays-with-sum
1029-vertical-order-traversal-of-a-binary-tree
1129-longest-string-chain
1264-maximum-number-of-words-you-can-type
1353-find-resultant-array-after-removing-anagrams
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1694-make-sum-divisible-by-p
1834-minimum-number-of-people-to-teach
1890-sum-of-beauty-of-all-substrings
2274-keep-multiplying-found-values-by-two
3242-count-elements-with-maximum-frequency
3819-count-covered-buildings
3934-coupon-code-validator

Two Pointers

0005-longest-palindromic-substring
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0295-find-median-from-data-stream
0455-assign-cookies
0567-permutation-in-string
0874-backspace-string-compare
0908-middle-of-the-linked-list
1129-longest-string-chain
2162-partition-array-into-two-arrays-to-minimize-sum-difference
2216-delete-the-middle-node-of-a-linked-list
2271-rearrange-array-elements-by-sign
2392-successful-pairs-of-spells-and-potions

String

0005-longest-palindromic-substring
0008-string-to-integer-atoi
0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0044-wildcard-matching
0058-length-of-last-word
0067-add-binary
0072-edit-distance
0125-valid-palindrome
0127-word-ladder
0151-reverse-words-in-a-string
0205-isomorphic-strings
0208-implement-trie-prefix-tree
0402-remove-k-digits
0451-sort-characters-by-frequency
0474-ones-and-zeroes
0516-longest-palindromic-subsequence
0567-permutation-in-string
0583-delete-operation-for-two-strings
0678-valid-parenthesis-string
0812-rotate-string
0874-backspace-string-compare
1078-remove-outermost-parentheses
1129-longest-string-chain
1170-shortest-common-supersequence
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1264-maximum-number-of-words-you-can-type
1353-find-resultant-array-after-removing-anagrams
1437-minimum-insertion-steps-to-make-a-string-palindrome
1460-number-of-substrings-containing-all-three-characters
1737-maximum-nesting-depth-of-the-parentheses
1890-sum-of-beauty-of-all-substrings
2032-largest-odd-number-in-string
2887-sort-vowels-in-a-string
3462-vowels-game-in-a-string
3934-coupon-code-validator

Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0678-valid-parenthesis-string
0735-asteroid-collision
0874-backspace-string-compare
0937-online-stock-span
0943-sum-of-subarray-minimums
1078-remove-outermost-parentheses
1197-parsing-a-boolean-expression
1737-maximum-nesting-depth-of-the-parentheses
2227-sum-of-subarray-ranges
2307-replace-non-coprime-numbers-in-array

Simulation

0067-add-binary
0258-add-digits
0498-diagonal-traverse
0735-asteroid-collision
0874-backspace-string-compare
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two

Sorting

0075-sort-colors
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0368-largest-divisible-subset
0414-third-maximum-number
0435-non-overlapping-intervals
0451-sort-characters-by-frequency
0455-assign-cookies
0594-longest-harmonious-subsequence
0621-task-scheduler
0759-set-intersection-size-at-least-two
0876-hand-of-straights
1014-k-closest-points-to-origin
1029-vertical-order-traversal-of-a-binary-tree
1129-longest-string-chain
1353-find-resultant-array-after-removing-anagrams
1669-minimum-cost-to-cut-a-stick
1966-frequency-of-the-most-frequent-element
2274-keep-multiplying-found-values-by-two
2392-successful-pairs-of-spells-and-potions
2887-sort-vowels-in-a-string
3620-maximum-number-of-distinct-elements-after-operations
3748-sort-matrix-by-diagonals
3819-count-covered-buildings
3934-coupon-code-validator

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
0621-task-scheduler
1890-sum-of-beauty-of-all-substrings
3242-count-elements-with-maximum-frequency

Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0110-balanced-binary-tree
0112-path-sum
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0789-kth-largest-element-in-a-stream
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0112-path-sum
0124-binary-tree-maximum-path-sum
0130-surrounded-regions
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0547-number-of-provinces
0662-maximum-width-of-binary-tree
0733-flood-fill
0794-swim-in-rising-water
0820-find-eventual-safe-states
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1073-number-of-enclaves
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0127-word-ladder
0130-surrounded-regions
0199-binary-tree-right-side-view
0226-invert-binary-tree
0322-coin-change
0547-number-of-provinces
0662-maximum-width-of-binary-tree
0733-flood-fill
0794-swim-in-rising-water
0820-find-eventual-safe-states
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1073-number-of-enclaves
1171-shortest-path-in-binary-matrix
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort

Binary Tree

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0110-balanced-binary-tree
0112-path-sum
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0543-diameter-of-binary-tree
0662-maximum-width-of-binary-tree
0789-kth-largest-element-in-a-stream
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0029-divide-two-integers
0048-rotate-image
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0189-rotate-array
0231-power-of-two
0258-add-digits
0368-largest-divisible-subset
1013-fibonacci-number
1014-k-closest-points-to-origin
1370-count-number-of-nice-subarrays
2032-largest-odd-number-in-string
2050-count-good-numbers
2233-number-of-smooth-descent-periods-of-a-stock
2307-replace-non-coprime-numbers-in-array
3279-alice-and-bob-playing-flower-game
3462-vowels-game-in-a-string
3864-count-the-number-of-computer-unlocking-permutations

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0355-design-twitter
0451-sort-characters-by-frequency
0621-task-scheduler
0789-kth-largest-element-in-a-stream
0794-swim-in-rising-water
1014-k-closest-points-to-origin
1127-last-stone-weight
1753-path-with-minimum-effort
1917-maximum-average-pass-ratio

Divide and Conquer

0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Bucket Sort

0347-top-k-frequent-elements
0451-sort-characters-by-frequency

Geometry

1014-k-closest-points-to-origin

Matrix

0048-rotate-image
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0130-surrounded-regions
0498-diagonal-traverse
0733-flood-fill
0794-swim-in-rising-water
0967-minimum-falling-path-sum
1036-rotting-oranges
1073-number-of-enclaves
1171-shortest-path-in-binary-matrix
1402-count-square-submatrices-with-all-ones
1753-path-with-minimum-effort
3748-sort-matrix-by-diagonals

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0044-wildcard-matching
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0123-best-time-to-buy-and-sell-stock-iii
0124-binary-tree-maximum-path-sum
0188-best-time-to-buy-and-sell-stock-iv
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0322-coin-change
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0474-ones-and-zeroes
0516-longest-palindromic-subsequence
0583-delete-operation-for-two-strings
0678-valid-parenthesis-string
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0943-sum-of-subarray-minimums
0967-minimum-falling-path-sum
1013-fibonacci-number
1129-longest-string-chain
1170-shortest-common-supersequence
1250-longest-common-subsequence
1402-count-square-submatrices-with-all-ones
1437-minimum-insertion-steps-to-make-a-string-palindrome
1586-longest-subarray-of-1s-after-deleting-one-element
1669-minimum-cost-to-cut-a-stick
2090-number-of-ways-to-arrive-at-destination
2162-partition-array-into-two-arrays-to-minimize-sum-difference
2233-number-of-smooth-descent-periods-of-a-stock

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0937-online-stock-span
0943-sum-of-subarray-minimums
2227-sum-of-subarray-ranges

Memoization

0070-climbing-stairs
1013-fibonacci-number

Merge Sort

0023-merge-k-sorted-lists
0148-sort-list

Bit Manipulation

0029-divide-two-integers
0067-add-binary
0078-subsets
0090-subsets-ii
0136-single-number
0222-count-complete-tree-nodes
0231-power-of-two
2162-partition-array-into-two-arrays-to-minimize-sum-difference

Number Theory

0258-add-digits
2307-replace-non-coprime-numbers-in-array

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0077-combinations
0078-subsets
0090-subsets-ii

Greedy

0044-wildcard-matching
0045-jump-game-ii
0055-jump-game
0135-candy
0402-remove-k-digits
0435-non-overlapping-intervals
0455-assign-cookies
0621-task-scheduler
0678-valid-parenthesis-string
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0759-set-intersection-size-at-least-two
0876-hand-of-straights
0890-lemonade-change
1834-minimum-number-of-people-to-teach
1917-maximum-average-pass-ratio
1966-frequency-of-the-most-frequent-element
2032-largest-odd-number-in-string
2618-maximize-the-minimum-powered-city
3620-maximum-number-of-distinct-elements-after-operations

String Matching

0812-rotate-string

Design

0146-lru-cache
0155-min-stack
0208-implement-trie-prefix-tree
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0355-design-twitter
0789-kth-largest-element-in-a-stream
0937-online-stock-span

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
2618-maximize-the-minimum-powered-city

Monotonic Queue

0239-sliding-window-maximum

Data Stream

0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream
0937-online-stock-span

Doubly-Linked List

0146-lru-cache

Binary Search Tree

0789-kth-largest-element-in-a-stream

Union Find

0130-surrounded-regions
0547-number-of-provinces
0794-swim-in-rising-water
1073-number-of-enclaves
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort

Graph

0547-number-of-provinces
0820-find-eventual-safe-states
1442-number-of-operations-to-make-network-connected
2090-number-of-ways-to-arrive-at-destination

Topological Sort

0820-find-eventual-safe-states
2090-number-of-ways-to-arrive-at-destination

Shortest Path

2090-number-of-ways-to-arrive-at-destination

Ordered Set

2162-partition-array-into-two-arrays-to-minimize-sum-difference

Bitmask

2162-partition-array-into-two-arrays-to-minimize-sum-difference

Trie

0208-implement-trie-prefix-tree

Brainteaser

3462-vowels-game-in-a-string
3864-count-the-number-of-computer-unlocking-permutations

Game Theory

3462-vowels-game-in-a-string

Combinatorics

3864-count-the-number-of-computer-unlocking-permutations