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

LeetCode Topics

Array

0036-valid-sudoku
0037-sudoku-solver
0073-set-matrix-zeroes
0075-sort-colors
0118-pascals-triangle
0135-candy
0498-diagonal-traverse
0594-longest-harmonious-subsequence
0679-24-game
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0945-snakes-and-ladders
1293-three-consecutive-odds
1350-remove-sub-folders-from-the-filesystem
1402-count-square-submatrices-with-all-ones
1424-maximum-candies-you-can-get-from-boxes
1426-find-n-unique-integers-sum-up-to-zero
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1586-longest-subarray-of-1s-after-deleting-one-element
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1628-count-submatrices-with-all-ones
1813-maximum-erasure-value
1834-minimum-number-of-people-to-teach
1851-maximum-number-of-events-that-can-be-attended-ii
1917-maximum-average-pass-ratio
1995-finding-pairs-with-a-certain-sum
2048-build-array-from-permutation
2079-delete-duplicate-folders-in-system
2144-maximum-difference-between-increasing-elements
2150-kth-smallest-product-of-two-sorted-arrays
2170-count-number-of-maximum-bitwise-or-subsets
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2229-maximum-fruits-harvested-after-at-most-k-steps
2237-longest-palindrome-by-concatenating-two-letter-words
2267-minimum-difference-in-sums-after-removal-of-elements
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2387-partition-array-such-that-maximum-difference-is-k
2400-minimum-score-after-removals-on-a-tree
2432-number-of-zero-filled-subarrays
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2529-range-product-queries-of-powers
2689-rearranging-fruits
2720-minimize-the-maximum-difference-of-pairs
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3194-find-words-containing-character
3241-divide-array-into-arrays-with-max-difference
3251-maximum-area-of-longest-diagonal-rectangle
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3744-minimum-operations-to-make-array-elements-zero
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3748-sort-matrix-by-diagonals
3788-maximum-unique-subarray-sum-after-deletion
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Simulation

0498-diagonal-traverse
2048-build-array-from-permutation
2260-divide-a-string-into-groups-of-size-k
2408-number-of-people-aware-of-a-secret
2479-meeting-rooms-iii
3600-find-the-k-th-character-in-string-game-i
3790-fruits-into-baskets-ii

Graph

1424-maximum-candies-you-can-get-from-boxes
1986-largest-color-value-in-a-directed-graph
2438-find-closest-node-to-given-two-nodes
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Heap (Priority Queue)

1478-maximum-number-of-events-that-can-be-attended
1917-maximum-average-pass-ratio
2204-find-subsequence-of-length-k-with-the-largest-sum
2267-minimum-difference-in-sums-after-removal-of-elements
2479-meeting-rooms-iii
3445-lexicographically-minimum-string-after-removing-stars
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii

Matrix

0036-valid-sudoku
0037-sudoku-solver
0073-set-matrix-zeroes
0498-diagonal-traverse
0945-snakes-and-ladders
1402-count-square-submatrices-with-all-ones
1628-count-submatrices-with-all-ones
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment
3748-sort-matrix-by-diagonals

Shortest Path

3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Math

0231-power-of-two
0326-power-of-three
0342-power-of-four
0679-24-game
0826-soup-servings
0867-new-21-game
0900-reordered-power-of-2
1411-convert-binary-number-in-a-linked-list-to-integer
1426-find-n-unique-integers-sum-up-to-zero
1440-convert-integer-to-the-sum-of-two-no-zero-integers
1448-maximum-69-number
1529-max-difference-you-can-get-from-changing-an-integer
2202-sum-of-k-mirror-numbers
2432-number-of-zero-filled-subarrays
2704-maximum-difference-by-remapping-a-digit
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
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
3321-type-of-triangle
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements
3744-minimum-operations-to-make-array-elements-zero
3754-maximum-manhattan-distance-after-k-changes
3830-find-closest-person

String

1058-lexicographically-smallest-equivalent-string
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1818-maximum-score-from-removing-substrings
2079-delete-duplicate-folders-in-system
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2346-largest-3-same-digit-number-in-string
2395-longest-binary-subsequence-less-than-or-equal-to-k
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3360-minimum-deletions-to-make-string-k-special
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3617-find-the-original-typed-string-i
3618-find-the-original-typed-string-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3683-find-the-lexicographically-largest-string-from-the-box-i
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3761-maximum-difference-between-even-and-odd-frequency-ii

Dynamic Programming

0118-pascals-triangle
0826-soup-servings
0867-new-21-game
0934-bitwise-ors-of-subarrays
1402-count-square-submatrices-with-all-ones
1586-longest-subarray-of-1s-after-deleting-one-element
1628-count-submatrices-with-all-ones
1851-maximum-number-of-events-that-can-be-attended-ii
1986-largest-color-value-in-a-directed-graph
2028-the-earliest-and-latest-rounds-where-players-compete
2061-painting-a-grid-with-three-different-colors
2267-minimum-difference-in-sums-after-removal-of-elements
2395-longest-binary-subsequence-less-than-or-equal-to-k
2408-number-of-people-aware-of-a-secret
2882-ways-to-express-an-integer-as-sum-of-powers
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3307-find-the-maximum-sum-of-node-values
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3618-find-the-original-typed-string-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment

Combinatorics

3201-distribute-candies-among-children-ii
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Greedy

0135-candy
1448-maximum-69-number
1478-maximum-number-of-events-that-can-be-attended
1529-max-difference-you-can-get-from-changing-an-integer
1818-maximum-score-from-removing-substrings
1834-minimum-number-of-people-to-teach
1917-maximum-average-pass-ratio
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2387-partition-array-such-that-maximum-difference-is-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2497-maximum-matching-of-players-with-trainers
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2689-rearranging-fruits
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3788-maximum-unique-subarray-sum-after-deletion

Hash Table

0036-valid-sudoku
0037-sudoku-solver
0073-set-matrix-zeroes
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
0940-fruit-into-baskets
1510-find-lucky-integer-in-an-array
1813-maximum-erasure-value
1834-minimum-number-of-people-to-teach
1986-largest-color-value-in-a-directed-graph
1995-finding-pairs-with-a-certain-sum
2079-delete-duplicate-folders-in-system
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2479-meeting-rooms-iii
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2689-rearranging-fruits
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3788-maximum-unique-subarray-sum-after-deletion

Sorting

0075-sort-colors
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2387-partition-array-such-that-maximum-difference-is-k
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2689-rearranging-fruits
3241-divide-array-into-arrays-with-max-difference
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3647-zero-array-transformation-iii
3748-sort-matrix-by-diagonals

Enumeration

0900-reordered-power-of-2
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets
2202-sum-of-k-mirror-numbers
2215-finding-3-digit-even-numbers
2837-minimum-operations-to-make-the-integer-zero
3201-distribute-candies-among-children-ii
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3459-find-the-minimum-area-to-cover-all-ones-ii
3683-find-the-lexicographically-largest-string-from-the-box-i
3741-reschedule-meetings-for-maximum-free-time-ii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Counting

0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1510-find-lucky-integer-in-an-array
1986-largest-color-value-in-a-directed-graph
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
3360-minimum-deletions-to-make-string-k-special
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Two Pointers

0075-sort-colors
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2320-find-all-k-distant-indices-in-an-array
2497-maximum-matching-of-players-with-trainers
3683-find-the-lexicographically-largest-string-from-the-box-i

Prefix Sum

2229-maximum-fruits-harvested-after-at-most-k-steps
2529-range-product-queries-of-powers
3618-find-the-original-typed-string-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Bit Manipulation

0231-power-of-two
0342-power-of-four
0934-bitwise-ors-of-subarrays
2170-count-number-of-maximum-bitwise-or-subsets
2400-minimum-score-after-removals-on-a-tree
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2529-range-product-queries-of-powers
2837-minimum-operations-to-make-the-integer-zero
3307-find-the-maximum-sum-of-node-values
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3744-minimum-operations-to-make-array-elements-zero

Tree

2400-minimum-score-after-removals-on-a-tree
3307-find-the-maximum-sum-of-node-values
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Topological Sort

1986-largest-color-value-in-a-directed-graph

Memoization

1986-largest-color-value-in-a-directed-graph
2028-the-earliest-and-latest-rounds-where-players-compete
2395-longest-binary-subsequence-less-than-or-equal-to-k
3733-length-of-longest-v-shaped-diagonal-segment

Depth-First Search

0386-lexicographical-numbers
1350-remove-sub-folders-from-the-filesystem
2400-minimum-score-after-removals-on-a-tree
2438-find-closest-node-to-given-two-nodes
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Breadth-First Search

0945-snakes-and-ladders
1424-maximum-candies-you-can-get-from-boxes
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Union Find

1058-lexicographically-smallest-equivalent-string

Stack

1628-count-submatrices-with-all-ones
1818-maximum-score-from-removing-substrings
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3445-lexicographically-minimum-string-after-removing-stars

Trie

0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem
2079-delete-duplicate-folders-in-system

Sliding Window

0594-longest-harmonious-subsequence
0867-new-21-game
0940-fruit-into-baskets
1586-longest-subarray-of-1s-after-deleting-one-element
1813-maximum-erasure-value
2229-maximum-fruits-harvested-after-at-most-k-steps
2498-smallest-subarrays-with-maximum-bitwise-or
3743-reschedule-meetings-for-maximum-free-time-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Binary Search

1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1851-maximum-number-of-events-that-can-be-attended-ii
2150-kth-smallest-product-of-two-sorted-arrays
2229-maximum-fruits-harvested-after-at-most-k-steps
2498-smallest-subarrays-with-maximum-bitwise-or
2720-minimize-the-maximum-difference-of-pairs
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Backtracking

0037-sudoku-solver
0679-24-game
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets

Recursion

0231-power-of-two
0326-power-of-three
0342-power-of-four
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Design

1995-finding-pairs-with-a-certain-sum

Linked List

1411-convert-binary-number-in-a-linked-list-to-integer

Hash Function

2079-delete-duplicate-folders-in-system

Segment Tree

3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and
2837-minimum-operations-to-make-the-integer-zero

Ordered Set

3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Probability and Statistics

0826-soup-servings
0867-new-21-game

Monotonic Stack

1628-count-submatrices-with-all-ones

Geometry

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

Queue

2408-number-of-people-aware-of-a-secret