LeetCode

A collection of LeetCode questions to ace the coding interview! - Created using LeetHub v2

LeetCode Topics

Array

0001-two-sum
0026-remove-duplicates-from-sorted-array
0036-valid-sudoku
0037-sudoku-solver
0066-plus-one
0088-merge-sorted-array
0334-increasing-triplet-subsequence
0335-self-crossing
0336-palindrome-pairs
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0363-max-sum-of-rectangle-no-larger-than-k
0373-find-k-pairs-with-smallest-sums
0378-kth-smallest-element-in-a-sorted-matrix
0407-trapping-rain-water-ii
0414-third-maximum-number
0417-pacific-atlantic-water-flow
0453-minimum-moves-to-equal-array-elements
0454-4sum-ii
0455-assign-cookies
0456-132-pattern
0463-island-perimeter
0475-heaters
0477-total-hamming-distance
0961-n-repeated-element-in-size-2n-array
0977-squares-of-a-sorted-array
0999-available-captures-for-rook
1002-find-common-characters
1004-max-consecutive-ones-iii
1005-maximize-sum-of-array-after-k-negations
1006-vowel-spellchecker
1008-construct-binary-search-tree-from-preorder-traversal
1010-pairs-of-songs-with-total-durations-divisible-by-60
1013-partition-array-into-three-parts-with-equal-sum
1018-binary-prefix-divisible-by-5
1019-next-greater-node-in-linked-list
1051-height-checker
1052-grumpy-bookstore-owner
1053-previous-permutation-with-one-swap
1200-minimum-absolute-difference
1351-count-negative-numbers-in-a-sorted-matrix
1390-four-divisors
1426-find-n-unique-integers-sum-up-to-zero
1612-avoid-flood-in-the-city
1834-minimum-number-of-people-to-teach
1917-maximum-average-pass-ratio
1975-maximum-matrix-sum
1991-find-the-middle-index-in-array
1992-find-all-groups-of-farmland
1995-count-special-quadruplets
1996-the-number-of-weak-characters-in-the-game
1998-gcd-sort-of-an-array
2001-number-of-pairs-of-interchangeable-rectangles
2007-find-original-array-from-doubled-array
2008-maximum-earnings-from-taxi
2011-final-value-of-variable-after-performing-operations
2012-sum-of-beauty-in-the-array
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2402-meeting-rooms-iii
2429-design-a-food-rating-system
3074-apple-redistribution-into-boxes
3075-maximize-happiness-of-selected-children
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3616-make-array-elements-equal-to-zero
3637-trionic-array-i
3719-longest-balanced-subarray-i
3733-length-of-longest-v-shaped-diagonal-segment
3744-minimum-operations-to-make-array-elements-zero
3748-sort-matrix-by-diagonals
3863-power-grid-maintenance

Dynamic Programming

1411-number-of-ways-to-paint-n-3-grid
2008-maximum-earnings-from-taxi
3733-length-of-longest-v-shaped-diagonal-segment

Memoization

3733-length-of-longest-v-shaped-diagonal-segment

Matrix

0036-valid-sudoku
0037-sudoku-solver
0363-max-sum-of-rectangle-no-larger-than-k
0378-kth-smallest-element-in-a-sorted-matrix
0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0463-island-perimeter
0999-available-captures-for-rook
1351-count-negative-numbers-in-a-sorted-matrix
1975-maximum-matrix-sum
1992-find-all-groups-of-farmland
3733-length-of-longest-v-shaped-diagonal-segment
3748-sort-matrix-by-diagonals

Sorting

0088-merge-sorted-array
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0378-kth-smallest-element-in-a-sorted-matrix
0414-third-maximum-number
0455-assign-cookies
0475-heaters
0977-squares-of-a-sorted-array
1005-maximize-sum-of-array-after-k-negations
1051-height-checker
1200-minimum-absolute-difference
1996-the-number-of-weak-characters-in-the-game
1998-gcd-sort-of-an-array
2007-find-original-array-from-doubled-array
2008-maximum-earnings-from-taxi
2402-meeting-rooms-iii
3074-apple-redistribution-into-boxes
3075-maximize-happiness-of-selected-children
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3748-sort-matrix-by-diagonals

Math

0002-add-two-numbers
0066-plus-one
0335-self-crossing
0453-minimum-moves-to-equal-array-elements
0477-total-hamming-distance
1390-four-divisors
1426-find-n-unique-integers-sum-up-to-zero
1642-water-bottles
1998-gcd-sort-of-an-array
2001-number-of-pairs-of-interchangeable-rectangles
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3279-alice-and-bob-playing-flower-game
3336-water-bottles-ii
3462-vowels-game-in-a-string
3744-minimum-operations-to-make-array-elements-zero
3830-find-closest-person

Hash Table

0001-two-sum
0036-valid-sudoku
0037-sudoku-solver
0336-palindrome-pairs
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0454-4sum-ii
0961-n-repeated-element-in-size-2n-array
1002-find-common-characters
1006-vowel-spellchecker
1010-pairs-of-songs-with-total-durations-divisible-by-60
1612-avoid-flood-in-the-city
1834-minimum-number-of-people-to-teach
1995-count-special-quadruplets
2001-number-of-pairs-of-interchangeable-rectangles
2007-find-original-array-from-doubled-array
2008-maximum-earnings-from-taxi
2402-meeting-rooms-iii
2429-design-a-food-rating-system
3713-longest-balanced-substring-i
3719-longest-balanced-subarray-i
3863-power-grid-maintenance

Backtracking

0037-sudoku-solver

Greedy

0334-increasing-triplet-subsequence
0455-assign-cookies
1005-maximize-sum-of-array-after-k-negations
1013-partition-array-into-three-parts-with-equal-sum
1053-previous-permutation-with-one-swap
1612-avoid-flood-in-the-city
1834-minimum-number-of-people-to-teach
1917-maximum-average-pass-ratio
1975-maximum-matrix-sum
1996-the-number-of-weak-characters-in-the-game
2007-find-original-array-from-doubled-array
3074-apple-redistribution-into-boxes
3075-maximize-happiness-of-selected-children

Heap (Priority Queue)

0373-find-k-pairs-with-smallest-sums
0378-kth-smallest-element-in-a-sorted-matrix
0407-trapping-rain-water-ii
1612-avoid-flood-in-the-city
1917-maximum-average-pass-ratio
2402-meeting-rooms-iii
2429-design-a-food-rating-system
3863-power-grid-maintenance

Two Pointers

0026-remove-duplicates-from-sorted-array
0088-merge-sorted-array
0165-compare-version-numbers
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0455-assign-cookies
0475-heaters
0696-count-binary-substrings
0977-squares-of-a-sorted-array

Geometry

0335-self-crossing
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i

Enumeration

1747-lexicographically-smallest-string-after-applying-operations
1995-count-special-quadruplets
2837-minimum-operations-to-make-the-integer-zero
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3713-longest-balanced-substring-i

Bit Manipulation

0190-reverse-bits
0477-total-hamming-distance
0693-binary-number-with-alternating-bits
1018-binary-prefix-divisible-by-5
2837-minimum-operations-to-make-the-integer-zero
3744-minimum-operations-to-make-array-elements-zero

Brainteaser

2837-minimum-operations-to-make-the-integer-zero
3462-vowels-game-in-a-string

String

0165-compare-version-numbers
0336-palindrome-pairs
0696-count-binary-substrings
1002-find-common-characters
1006-vowel-spellchecker
1747-lexicographically-smallest-string-after-applying-operations
2011-final-value-of-variable-after-performing-operations
2429-design-a-food-rating-system
2483-minimum-penalty-for-a-shop
3462-vowels-game-in-a-string
3713-longest-balanced-substring-i

Game Theory

3462-vowels-game-in-a-string

Stack

0456-132-pattern
1008-construct-binary-search-tree-from-preorder-traversal
1019-next-greater-node-in-linked-list
1996-the-number-of-weak-characters-in-the-game
2307-replace-non-coprime-numbers-in-array

Number Theory

1998-gcd-sort-of-an-array
2001-number-of-pairs-of-interchangeable-rectangles
2307-replace-non-coprime-numbers-in-array

Design

2429-design-a-food-rating-system

Ordered Set

0363-max-sum-of-rectangle-no-larger-than-k
0456-132-pattern
2429-design-a-food-rating-system
3863-power-grid-maintenance

Linked List

0002-add-two-numbers
1019-next-greater-node-in-linked-list

Recursion

0002-add-two-numbers

Simulation

0999-available-captures-for-rook
1642-water-bottles
2011-final-value-of-variable-after-performing-operations
2324-find-triangular-sum-of-an-array
2402-meeting-rooms-iii
3336-water-bottles-ii
3616-make-array-elements-equal-to-zero

Combinatorics

2324-find-triangular-sum-of-an-array

Breadth-First Search

0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0463-island-perimeter
1747-lexicographically-smallest-string-after-applying-operations
1992-find-all-groups-of-farmland
3863-power-grid-maintenance

Depth-First Search

0417-pacific-atlantic-water-flow
0463-island-perimeter
1747-lexicographically-smallest-string-after-applying-operations
1992-find-all-groups-of-farmland
3863-power-grid-maintenance

Binary Search

0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0363-max-sum-of-rectangle-no-larger-than-k
0374-guess-number-higher-or-lower
0378-kth-smallest-element-in-a-sorted-matrix
0456-132-pattern
0475-heaters
1004-max-consecutive-ones-iii
1351-count-negative-numbers-in-a-sorted-matrix
1612-avoid-flood-in-the-city
2008-maximum-earnings-from-taxi

Prefix Sum

0363-max-sum-of-rectangle-no-larger-than-k
1004-max-consecutive-ones-iii
1991-find-the-middle-index-in-array
2483-minimum-penalty-for-a-shop
3616-make-array-elements-equal-to-zero
3719-longest-balanced-subarray-i

Union Find

3863-power-grid-maintenance

Graph

3863-power-grid-maintenance

Trie

0336-palindrome-pairs

Monotonic Stack

0456-132-pattern
1008-construct-binary-search-tree-from-preorder-traversal
1019-next-greater-node-in-linked-list
1996-the-number-of-weak-characters-in-the-game

Database

0175-combine-two-tables
0176-second-highest-salary
0177-nth-highest-salary
0178-rank-scores
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0196-delete-duplicate-emails
0197-rising-temperature
0511-game-play-analysis-i
0577-employee-bonus
0584-find-customer-referee
0585-investments-in-2016
0586-customer-placing-the-largest-number-of-orders
0607-sales-person
0620-not-boring-movies
1527-patients-with-a-condition
1741-find-total-time-spent-by-each-employee

Interactive

0374-guess-number-higher-or-lower

Divide and Conquer

0190-reverse-bits
3719-longest-balanced-subarray-i

Segment Tree

3719-longest-balanced-subarray-i

Counting

1010-pairs-of-songs-with-total-durations-divisible-by-60
2001-number-of-pairs-of-interchangeable-rectangles
3713-longest-balanced-substring-i

Union-Find

1998-gcd-sort-of-an-array

Sliding Window

1004-max-consecutive-ones-iii
1052-grumpy-bookstore-owner

Tree

1008-construct-binary-search-tree-from-preorder-traversal

Binary Search Tree

1008-construct-binary-search-tree-from-preorder-traversal

Binary Tree

1008-construct-binary-search-tree-from-preorder-traversal

Counting Sort

1051-height-checker