LeetCode Solutions

This repository contains my structured solutions to LeetCode problems. I use this space to strengthen my understanding of Data Structures and Algorithms, improve problem-solving skills, and write optimized, clean implementations.

My focus is on correctness, efficiency, and maintaining clear logic rather than just reaching the final answer.

LeetCode Topics

Array


0001-two-sum
0004-median-of-two-sorted-arrays
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0039-combination-sum
0042-trapping-rain-water
0046-permutations
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0054-spiral-matrix
0056-merge-intervals
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0217-contains-duplicate
0229-majority-element-ii
0283-move-zeroes
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0485-max-consecutive-ones
0493-reverse-pairs
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0643-maximum-average-subarray-i
0704-binary-search
0875-koko-eating-bananas
0961-n-repeated-element-in-size-2n-array
1095-find-in-mountain-array
1351-count-negative-numbers-in-a-sorted-matrix
1365-how-many-numbers-are-smaller-than-the-current-number
1431-kids-with-the-greatest-number-of-candies
1582-special-positions-in-a-binary-matrix
1637-widest-vertical-area-between-two-points-containing-no-points
1679-max-number-of-k-sum-pairs
1769-minimum-number-of-operations-to-move-all-balls-to-each-box
1980-find-unique-binary-string
2011-final-value-of-variable-after-performing-operations
2149-rearrange-array-elements-by-sign
2344-minimum-deletions-to-make-array-divisible
2401-longest-nice-subarray
2553-separate-the-digits-in-an-array
2574-left-and-right-sum-differences
2789-largest-element-in-an-array-after-merge-operations
2932-maximum-strong-pair-xor-i
2942-find-words-containing-character
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3264-final-array-state-after-k-multiplication-operations-i
3467-transform-array-by-parity
3833-count-dominant-indices
3834-merge-adjacent-equal-elements
3847-find-the-score-difference-in-a-game

Hash Table


0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0036-valid-sudoku
0049-group-anagrams
0073-set-matrix-zeroes
0169-majority-element
0202-happy-number
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0347-top-k-frequent-elements
0560-subarray-sum-equals-k
0961-n-repeated-element-in-size-2n-array
1365-how-many-numbers-are-smaller-than-the-current-number
1679-max-number-of-k-sum-pairs
1980-find-unique-binary-string
2932-maximum-strong-pair-xor-i
3760-maximum-substrings-with-distinct-start

Binary Search


0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0287-find-the-duplicate-number
0493-reverse-pairs
0540-single-element-in-a-sorted-array
0704-binary-search
0875-koko-eating-bananas
1095-find-in-mountain-array
1351-count-negative-numbers-in-a-sorted-matrix
3600-maximize-spanning-tree-stability-with-upgrades

Divide and Conquer


0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0169-majority-element
0347-top-k-frequent-elements
0493-reverse-pairs

Math


0002-add-two-numbers
0009-palindrome-number
0013-roman-to-integer
0048-rotate-image
0066-plus-one
0150-evaluate-reverse-polish-notation
0189-rotate-array
0202-happy-number
0224-basic-calculator
0258-add-digits
0326-power-of-three
1281-subtract-the-product-and-sum-of-digits-of-an-integer
1342-number-of-steps-to-reduce-a-number-to-zero
1523-count-odd-numbers-in-an-interval-range
1688-count-of-matches-in-tournament
1925-count-square-sum-triples
2160-minimum-sum-of-four-digit-number-after-splitting-digits
2235-add-two-integers
2344-minimum-deletions-to-make-array-divisible
2396-strictly-palindromic-number
2520-count-the-digits-that-divide-a-number
3264-final-array-state-after-k-multiplication-operations-i

Matrix


0036-valid-sudoku
0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0200-number-of-islands
1351-count-negative-numbers-in-a-sorted-matrix
1582-special-positions-in-a-binary-matrix

Sorting


0015-3sum
0018-4sum
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0347-top-k-frequent-elements
1365-how-many-numbers-are-smaller-than-the-current-number
1637-widest-vertical-area-between-two-points-containing-no-points
1679-max-number-of-k-sum-pairs
2160-minimum-sum-of-four-digit-number-after-splitting-digits
2344-minimum-deletions-to-make-array-divisible
3467-transform-array-by-parity

Counting Sort


0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
1365-how-many-numbers-are-smaller-than-the-current-number
3467-transform-array-by-parity

String


0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0022-generate-parentheses
0032-longest-valid-parentheses
0049-group-anagrams
0125-valid-palindrome
0151-reverse-words-in-a-string
0224-basic-calculator
0242-valid-anagram
0344-reverse-string
0392-is-subsequence
0557-reverse-words-in-a-string-iii
0680-valid-palindrome-ii
0709-to-lower-case
1047-remove-all-adjacent-duplicates-in-string
1108-defanging-an-ip-address
1545-find-kth-bit-in-nth-binary-string
1689-partitioning-into-minimum-number-of-deci-binary-numbers
1758-minimum-changes-to-make-alternating-binary-string
1768-merge-strings-alternately
1769-minimum-number-of-operations-to-move-all-balls-to-each-box
1784-check-if-binary-string-has-at-most-one-segment-of-ones
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
1980-find-unique-binary-string
2011-final-value-of-variable-after-performing-operations
2942-find-words-containing-character
3110-score-of-a-string
3760-maximum-substrings-with-distinct-start

Stack


0032-longest-valid-parentheses
0042-trapping-rain-water
0114-flatten-binary-tree-to-linked-list
0150-evaluate-reverse-polish-notation
0224-basic-calculator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
1047-remove-all-adjacent-duplicates-in-string
3834-merge-adjacent-equal-elements

Two Pointers


0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0042-trapping-rain-water
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0125-valid-palindrome
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0392-is-subsequence
0557-reverse-words-in-a-string-iii
0680-valid-palindrome-ii
1679-max-number-of-k-sum-pairs
1768-merge-strings-alternately
2149-rearrange-array-elements-by-sign
2396-strictly-palindromic-number

Greedy


0680-valid-palindrome-ii
1689-partitioning-into-minimum-number-of-deci-binary-numbers
2160-minimum-sum-of-four-digit-number-after-splitting-digits
2789-largest-element-in-an-array-after-merge-operations
3600-maximize-spanning-tree-stability-with-upgrades

Enumeration


1925-count-square-sum-triples
3827-count-monobit-integers
3833-count-dominant-indices

Bit Manipulation


0287-find-the-duplicate-number
0693-binary-number-with-alternating-bits
1009-complement-of-base-10-integer
1342-number-of-steps-to-reduce-a-number-to-zero
2401-longest-nice-subarray
2932-maximum-strong-pair-xor-i
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3827-count-monobit-integers

Heap (Priority Queue)


0023-merge-k-sorted-lists
0347-top-k-frequent-elements
2344-minimum-deletions-to-make-array-divisible
3264-final-array-state-after-k-multiplication-operations-i

Simulation


0054-spiral-matrix
0258-add-digits
1545-find-kth-bit-in-nth-binary-string
1688-count-of-matches-in-tournament
2011-final-value-of-variable-after-performing-operations
2149-rearrange-array-elements-by-sign
2553-separate-the-digits-in-an-array
3264-final-array-state-after-k-multiplication-operations-i
3834-merge-adjacent-equal-elements
3847-find-the-score-difference-in-a-game

Brainteaser


2396-strictly-palindromic-number

Prefix Sum


0560-subarray-sum-equals-k
1769-minimum-number-of-operations-to-move-all-balls-to-each-box
2574-left-and-right-sum-differences
3129-find-all-possible-stable-binary-arrays-i
3130-find-all-possible-stable-binary-arrays-ii
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Recursion


0002-add-two-numbers
0021-merge-two-sorted-lists
0224-basic-calculator
0234-palindrome-linked-list
0326-power-of-three
1545-find-kth-bit-in-nth-binary-string

Number Theory


0258-add-digits
2344-minimum-deletions-to-make-array-divisible

Trie


2932-maximum-strong-pair-xor-i

Sliding Window


0003-longest-substring-without-repeating-characters
0643-maximum-average-subarray-i
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
2401-longest-nice-subarray
2932-maximum-strong-pair-xor-i
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Dynamic Programming


0022-generate-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0053-maximum-subarray
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0198-house-robber
0392-is-subsequence
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
3129-find-all-possible-stable-binary-arrays-i
3130-find-all-possible-stable-binary-arrays-ii

Binary Indexed Tree


0493-reverse-pairs

Segment Tree


0493-reverse-pairs

Merge Sort


0023-merge-k-sorted-lists
0493-reverse-pairs

Ordered Set


0493-reverse-pairs

Linked List


0002-add-two-numbers
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0114-flatten-binary-tree-to-linked-list
0234-palindrome-linked-list

Tree


0103-binary-tree-zigzag-level-order-traversal
0114-flatten-binary-tree-to-linked-list
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0543-diameter-of-binary-tree
0700-search-in-a-binary-search-tree

Depth-First Search


0114-flatten-binary-tree-to-linked-list
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0200-number-of-islands
0543-diameter-of-binary-tree

Binary Tree


0103-binary-tree-zigzag-level-order-traversal
0114-flatten-binary-tree-to-linked-list
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0543-diameter-of-binary-tree
0700-search-in-a-binary-search-tree

Breadth-First Search


0103-binary-tree-zigzag-level-order-traversal
0199-binary-tree-right-side-view
0200-number-of-islands

Queue


0225-implement-stack-using-queues
0232-implement-queue-using-stacks
3191-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Design


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

Union-Find


0200-number-of-islands
3600-maximize-spanning-tree-stability-with-upgrades

Monotonic Stack


0042-trapping-rain-water

Backtracking


0022-generate-parentheses
0039-combination-sum
0046-permutations
1980-find-unique-binary-string

Interactive


1095-find-in-mountain-array

Database


0197-rising-temperature
0584-find-customer-referee
0595-big-countries
1068-product-sales-analysis-i
1148-article-views-i
1378-replace-employee-id-with-the-unique-identifier
1581-customer-who-visited-but-did-not-make-any-transactions
1683-invalid-tweets

Graph Theory


3600-maximize-spanning-tree-stability-with-upgrades

Minimum Spanning Tree


3600-maximize-spanning-tree-stability-with-upgrades

Binary Search Tree


0700-search-in-a-binary-search-tree

Bucket Sort


0347-top-k-frequent-elements

Quickselect


0347-top-k-frequent-elements

Name	Name	Last commit message	Last commit date
Latest commit History 604 Commits 604 Commits
0001-two-sum	0001-two-sum
0002-add-two-numbers	0002-add-two-numbers
0003-longest-substring-without-repeating-characters	0003-longest-substring-without-repeating-characters
0004-median-of-two-sorted-arrays	0004-median-of-two-sorted-arrays
0009-palindrome-number	0009-palindrome-number
0013-roman-to-integer	0013-roman-to-integer
0015-3sum	0015-3sum
0018-4sum	0018-4sum
0021-merge-two-sorted-lists	0021-merge-two-sorted-lists
0022-generate-parentheses	0022-generate-parentheses
0023-merge-k-sorted-lists	0023-merge-k-sorted-lists
0026-remove-duplicates-from-sorted-array	0026-remove-duplicates-from-sorted-array
0031-next-permutation	0031-next-permutation
0032-longest-valid-parentheses	0032-longest-valid-parentheses
0033-search-in-rotated-sorted-array	0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array	0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position	0035-search-insert-position
0036-valid-sudoku	0036-valid-sudoku
0039-combination-sum	0039-combination-sum
0042-trapping-rain-water	0042-trapping-rain-water
0046-permutations	0046-permutations
0048-rotate-image	0048-rotate-image
0049-group-anagrams	0049-group-anagrams
0053-maximum-subarray	0053-maximum-subarray
0054-spiral-matrix	0054-spiral-matrix
0056-merge-intervals	0056-merge-intervals
0066-plus-one	0066-plus-one
0073-set-matrix-zeroes	0073-set-matrix-zeroes
0075-sort-colors	0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii	0080-remove-duplicates-from-sorted-array-ii
0081-search-in-rotated-sorted-array-ii	0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array	0088-merge-sorted-array
0103-binary-tree-zigzag-level-order-traversal	0103-binary-tree-zigzag-level-order-traversal
0114-flatten-binary-tree-to-linked-list	0114-flatten-binary-tree-to-linked-list
0118-pascals-triangle	0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock	0121-best-time-to-buy-and-sell-stock
0125-valid-palindrome	0125-valid-palindrome
0129-sum-root-to-leaf-numbers	0129-sum-root-to-leaf-numbers
0150-evaluate-reverse-polish-notation	0150-evaluate-reverse-polish-notation
0151-reverse-words-in-a-string	0151-reverse-words-in-a-string
0152-maximum-product-subarray	0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array	0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element	0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted	0167-two-sum-ii-input-array-is-sorted
0169-majority-element	0169-majority-element
0189-rotate-array	0189-rotate-array
0197-rising-temperature	0197-rising-temperature
0198-house-robber	0198-house-robber
0199-binary-tree-right-side-view	0199-binary-tree-right-side-view
0200-number-of-islands	0200-number-of-islands
0202-happy-number	0202-happy-number
0217-contains-duplicate	0217-contains-duplicate
0224-basic-calculator	0224-basic-calculator
0225-implement-stack-using-queues	0225-implement-stack-using-queues
0229-majority-element-ii	0229-majority-element-ii
0232-implement-queue-using-stacks	0232-implement-queue-using-stacks
0234-palindrome-linked-list	0234-palindrome-linked-list
0242-valid-anagram	0242-valid-anagram
0258-add-digits	0258-add-digits
0283-move-zeroes	0283-move-zeroes
0287-find-the-duplicate-number	0287-find-the-duplicate-number
0326-power-of-three	0326-power-of-three
0344-reverse-string	0344-reverse-string
0347-top-k-frequent-elements	0347-top-k-frequent-elements
0392-is-subsequence	0392-is-subsequence
0485-max-consecutive-ones	0485-max-consecutive-ones
0493-reverse-pairs	0493-reverse-pairs
0540-single-element-in-a-sorted-array	0540-single-element-in-a-sorted-array
0543-diameter-of-binary-tree	0543-diameter-of-binary-tree
0557-reverse-words-in-a-string-iii	0557-reverse-words-in-a-string-iii
0560-subarray-sum-equals-k	0560-subarray-sum-equals-k
0584-find-customer-referee	0584-find-customer-referee
0595-big-countries	0595-big-countries
0643-maximum-average-subarray-i	0643-maximum-average-subarray-i
0680-valid-palindrome-ii	0680-valid-palindrome-ii
0693-binary-number-with-alternating-bits	0693-binary-number-with-alternating-bits
0700-search-in-a-binary-search-tree	0700-search-in-a-binary-search-tree
0704-binary-search	0704-binary-search
0709-to-lower-case	0709-to-lower-case
0875-koko-eating-bananas	0875-koko-eating-bananas
0961-n-repeated-element-in-size-2n-array	0961-n-repeated-element-in-size-2n-array
1009-complement-of-base-10-integer	1009-complement-of-base-10-integer
1047-remove-all-adjacent-duplicates-in-string	1047-remove-all-adjacent-duplicates-in-string
1068-product-sales-analysis-i	1068-product-sales-analysis-i
1095-find-in-mountain-array	1095-find-in-mountain-array
1108-defanging-an-ip-address	1108-defanging-an-ip-address
1148-article-views-i	1148-article-views-i
1281-subtract-the-product-and-sum-of-digits-of-an-integer	1281-subtract-the-product-and-sum-of-digits-of-an-integer
1342-number-of-steps-to-reduce-a-number-to-zero	1342-number-of-steps-to-reduce-a-number-to-zero
1351-count-negative-numbers-in-a-sorted-matrix	1351-count-negative-numbers-in-a-sorted-matrix
1365-how-many-numbers-are-smaller-than-the-current-number	1365-how-many-numbers-are-smaller-than-the-current-number
1378-replace-employee-id-with-the-unique-identifier	1378-replace-employee-id-with-the-unique-identifier
1431-kids-with-the-greatest-number-of-candies	1431-kids-with-the-greatest-number-of-candies
1523-count-odd-numbers-in-an-interval-range	1523-count-odd-numbers-in-an-interval-range
1545-find-kth-bit-in-nth-binary-string	1545-find-kth-bit-in-nth-binary-string
1581-customer-who-visited-but-did-not-make-any-transactions	1581-customer-who-visited-but-did-not-make-any-transactions
1582-special-positions-in-a-binary-matrix	1582-special-positions-in-a-binary-matrix
1637-widest-vertical-area-between-two-points-containing-no-points	1637-widest-vertical-area-between-two-points-containing-no-points
1679-max-number-of-k-sum-pairs	1679-max-number-of-k-sum-pairs
1683-invalid-tweets	1683-invalid-tweets

Search code, repositories, users, issues, pull requests...

Folders and files

Latest commit

History

Repository files navigation

LeetCode Solutions

LeetCode Topics

Array

Hash Table

Binary Search

Divide and Conquer

Math

Matrix

Sorting

Counting Sort

String

Stack

Two Pointers

Greedy

Enumeration

Bit Manipulation

Heap (Priority Queue)

Simulation

Brainteaser

Prefix Sum

Recursion

Number Theory

Trie

Sliding Window

Dynamic Programming

Binary Indexed Tree

Segment Tree

Merge Sort

Ordered Set

Linked List

Tree

Depth-First Search

Binary Tree

Breadth-First Search

Queue

Design

Union-Find

Monotonic Stack

Backtracking

Interactive

Database

Graph Theory

Minimum Spanning Tree

Binary Search Tree

Bucket Sort

Quickselect

About

Topics

Resources

Uh oh!

Stars

Watchers

Forks

Releases

Packages 0

Uh oh!

Contributors

Uh oh!

Languages

Packages