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

LeetCode Topics

Hash Table

0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0169-majority-element
0187-repeated-dna-sequences
0229-majority-element-ii
0264-ugly-number-ii
0266-palindrome-permutation
0325-maximum-size-subarray-sum-equals-k
0350-intersection-of-two-arrays-ii
0380-insert-delete-getrandom-o1
0496-next-greater-element-i
0525-contiguous-array
0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence
0768-partition-labels
0797-rabbits-in-forest
0837-most-common-word
0906-walking-robot-simulation
1084-find-k-length-substrings-with-no-repeated-characters
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1500-count-largest-group
1556-make-two-arrays-equal-by-reversing-subarrays
1903-design-most-recently-used-queue
1915-check-if-one-string-swap-can-make-strings-equal
2003-distinct-numbers-in-each-subarray
2163-kth-distinct-string-in-an-array
2306-create-binary-tree-from-descriptions
2308-divide-array-into-equal-pairs
2434-design-a-number-container-system
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2707-merge-two-2d-arrays-by-summing-values
2915-count-of-interesting-subarrays
3227-find-missing-and-repeated-values
3434-find-the-number-of-distinct-colors-among-the-balls
3501-delete-nodes-from-linked-list-present-in-array

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0029-divide-two-integers
0048-rotate-image
0050-powx-n
0066-plus-one
0189-rotate-array
0263-ugly-number
0264-ugly-number-ii
0380-insert-delete-getrandom-o1
0539-minimum-time-difference
0556-next-greater-element-iii
0633-sum-of-square-numbers
0650-2-keys-keyboard
0797-rabbits-in-forest
1013-fibonacci-number
1370-count-number-of-nice-subarrays
1426-find-n-unique-integers-sum-up-to-zero
1500-count-largest-group
1631-number-of-sub-arrays-with-odd-sum
1642-water-bottles
1889-check-if-number-is-a-sum-of-powers-of-three
1951-find-the-winner-of-the-circular-game
2050-count-good-numbers
2155-find-missing-observations
2415-count-the-number-of-ideal-arrays
2448-count-number-of-bad-pairs
2610-closest-prime-numbers-in-range
2644-bitwise-or-of-all-subsequence-sums
2645-pass-the-pillow
2649-count-total-number-of-colored-cells
2704-maximum-difference-by-remapping-a-digit
2802-find-the-punishment-number-of-an-integer
2903-insert-greatest-common-divisors-in-linked-list
3227-find-missing-and-repeated-values
3321-type-of-triangle
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0008-string-to-integer-atoi
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0038-count-and-say
0125-valid-palindrome
0151-reverse-words-in-a-string
0187-repeated-dna-sequences
0266-palindrome-permutation
0539-minimum-time-difference
0556-next-greater-element-iii
0768-partition-labels
0837-most-common-word
1051-shortest-way-to-form-string
1084-find-k-length-substrings-with-no-repeated-characters
1170-shortest-common-supersequence
1460-number-of-substrings-containing-all-three-characters
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1915-check-if-one-string-swap-can-make-strings-equal
2021-remove-all-occurrences-of-a-substring
2076-sum-of-digits-of-string-after-convert
2163-kth-distinct-string-in-an-array
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2502-sort-the-people
2727-number-of-senior-citizens
3447-clear-digits
3484-lexicographically-smallest-string-after-a-swap
3617-find-the-original-typed-string-i
3683-find-the-lexicographically-largest-string-from-the-box-i

Array

0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0033-search-in-rotated-sorted-array
0040-combination-sum-ii
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0053-maximum-subarray
0054-spiral-matrix
0059-spiral-matrix-ii
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0134-gas-station
0135-candy
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0229-majority-element-ii
0255-verify-preorder-sequence-in-binary-search-tree
0274-h-index
0300-longest-increasing-subsequence
0302-smallest-rectangle-enclosing-black-pixels
0317-shortest-distance-from-all-buildings
0325-maximum-size-subarray-sum-equals-k
0330-patching-array
0350-intersection-of-two-arrays-ii
0380-insert-delete-getrandom-o1
0414-third-maximum-number
0416-partition-equal-subset-sum
0487-max-consecutive-ones-ii
0496-next-greater-element-i
0502-ipo
0525-contiguous-array
0539-minimum-time-difference
0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence
0735-asteroid-collision
0797-rabbits-in-forest
0837-most-common-word
0853-most-profit-assigning-work
0890-lemonade-change
0906-walking-robot-simulation
0982-minimum-increment-to-make-array-unique
1049-minimum-domino-rotations-for-equal-row
1138-grumpy-bookstore-owner
1227-number-of-equivalent-domino-pairs
1293-three-consecutive-odds
1335-maximum-candies-allocated-to-k-children
1364-tuple-with-same-product
1370-count-number-of-nice-subarrays
1426-find-n-unique-integers-sum-up-to-zero
1478-maximum-number-of-events-that-can-be-attended
1511-count-number-of-teams
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1556-make-two-arrays-equal-by-reversing-subarrays
1605-minimum-number-of-days-to-make-m-bouquets
1615-range-sum-of-sorted-subarray-sums
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1631-number-of-sub-arrays-with-odd-sum
1656-count-good-triplets
1675-magnetic-force-between-two-balls
1803-average-waiting-time
1819-construct-the-lexicographically-largest-valid-sequence
1849-maximum-absolute-sum-of-any-subarray
1878-check-if-array-is-sorted-and-rotated
1903-design-most-recently-used-queue
1927-maximum-ascending-subarray-sum
1951-find-the-winner-of-the-circular-game
2003-distinct-numbers-in-each-subarray
2006-find-the-student-that-will-replace-the-chalk
2020-remove-one-element-to-make-the-array-strictly-increasing
2132-convert-1d-array-into-2d-array
2144-maximum-difference-between-increasing-elements
2148-minimum-number-of-moves-to-seat-everyone
2155-find-missing-observations
2163-kth-distinct-string-in-an-array
2180-maximum-number-of-tasks-you-can-assign
2255-minimum-swaps-to-group-all-1s-together-ii
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2277-count-equal-and-divisible-pairs-in-an-array
2306-create-binary-tree-from-descriptions
2308-divide-array-into-equal-pairs
2394-count-subarrays-with-score-less-than-k
2411-spiral-matrix-iv
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2527-count-subarrays-with-fixed-bounds
2551-apply-operations-to-an-array
2614-maximum-count-of-positive-integer-and-negative-integer
2644-bitwise-or-of-all-subsequence-sums
2665-minimum-time-to-repair-cars
2674-make-the-prefix-sum-non-negative
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
2720-minimize-the-maximum-difference-of-pairs
2727-number-of-senior-citizens
2875-count-houses-in-a-circular-street
2915-count-of-interesting-subarrays
3227-find-missing-and-repeated-values
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3332-minimum-operations-to-exceed-threshold-value-ii
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3434-find-the-number-of-distinct-colors-among-the-balls
3463-alternating-groups-i
3469-maximum-height-of-a-triangle
3471-minimum-average-of-smallest-and-largest-elements
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3490-find-the-maximum-length-of-valid-subsequence-i
3501-delete-nodes-from-linked-list-present-in-array
3643-zero-array-transformation-ii

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0125-valid-palindrome
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0350-intersection-of-two-arrays-ii
0556-next-greater-element-iii
0633-sum-of-square-numbers
0768-partition-labels
0853-most-profit-assigning-work
1051-shortest-way-to-form-string
1615-range-sum-of-sorted-subarray-sums
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2551-apply-operations-to-an-array
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3471-minimum-average-of-smallest-and-largest-elements
3683-find-the-lexicographically-largest-string-from-the-box-i

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0075-sort-colors
0169-majority-element
0229-majority-element-ii
0274-h-index
0350-intersection-of-two-arrays-ii
0414-third-maximum-number
0502-ipo
0539-minimum-time-difference
0594-longest-harmonious-subsequence
0853-most-profit-assigning-work
0982-minimum-increment-to-make-array-unique
1478-maximum-number-of-events-that-can-be-attended
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1675-magnetic-force-between-two-balls
2148-minimum-number-of-moves-to-seat-everyone
2180-maximum-number-of-tasks-you-can-assign
2379-maximum-total-importance-of-roads
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2699-count-the-number-of-fair-pairs
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3471-minimum-average-of-smallest-and-largest-elements

Bit Manipulation

0029-divide-two-integers
0187-repeated-dna-sequences
0266-palindrome-permutation
0476-number-complement
2308-divide-array-into-equal-pairs
2323-minimum-bit-flips-to-convert-number
2644-bitwise-or-of-all-subsequence-sums
3307-find-the-maximum-sum-of-node-values
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3508-number-of-bit-changes-to-make-two-integers-equal

Greedy

0011-container-with-most-water
0045-jump-game-ii
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0135-candy
0330-patching-array
0502-ipo
0768-partition-labels
0797-rabbits-in-forest
0853-most-profit-assigning-work
0890-lemonade-change
0982-minimum-increment-to-make-array-unique
1049-minimum-domino-rotations-for-equal-row
1051-shortest-way-to-form-string
1285-balance-a-binary-search-tree
1478-maximum-number-of-events-that-can-be-attended
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
2148-minimum-number-of-moves-to-seat-everyone
2180-maximum-number-of-tasks-you-can-assign
2379-maximum-total-importance-of-roads
2674-make-the-prefix-sum-non-negative
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3307-find-the-maximum-sum-of-node-values
3484-lexicographically-smallest-string-after-a-swap

Counting

0169-majority-element
0229-majority-element-ii
0594-longest-harmonious-subsequence
0837-most-common-word
0982-minimum-increment-to-make-array-unique
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1915-check-if-one-string-swap-can-make-strings-equal
2163-kth-distinct-string-in-an-array
2308-divide-array-into-equal-pairs
2448-count-number-of-bad-pairs
2614-maximum-count-of-positive-integer-and-negative-integer

Heap (Priority Queue)

0023-merge-k-sorted-lists
0264-ugly-number-ii
0502-ipo
1478-maximum-number-of-events-that-can-be-attended
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
2379-maximum-total-importance-of-roads
2434-design-a-number-container-system
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2674-make-the-prefix-sum-non-negative
3332-minimum-operations-to-exceed-threshold-value-ii

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0061-rotate-list
1484-linked-list-in-binary-tree
2182-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2299-merge-nodes-in-between-zeros
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0050-powx-n
0255-verify-preorder-sequence-in-binary-search-tree
1013-fibonacci-number
1951-find-the-winner-of-the-circular-game
2050-count-good-numbers

Counting Sort

0274-h-index
2148-minimum-number-of-moves-to-seat-everyone

Binary Search

0033-search-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0300-longest-increasing-subsequence
0302-smallest-rectangle-enclosing-black-pixels
0350-intersection-of-two-arrays-ii
0633-sum-of-square-numbers
0853-most-profit-assigning-work
1051-shortest-way-to-form-string
1335-maximum-candies-allocated-to-k-children
1605-minimum-number-of-days-to-make-m-bouquets
1615-range-sum-of-sorted-subarray-sums
1675-magnetic-force-between-two-balls
2006-find-the-student-that-will-replace-the-chalk
2180-maximum-number-of-tasks-you-can-assign
2394-count-subarrays-with-score-less-than-k
2614-maximum-count-of-positive-integer-and-negative-integer
2665-minimum-time-to-repair-cars
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
3643-zero-array-transformation-ii

Divide and Conquer

0023-merge-k-sorted-lists
0053-maximum-subarray
0169-majority-element
1285-balance-a-binary-search-tree

Tree

0144-binary-tree-preorder-traversal
0255-verify-preorder-sequence-in-binary-search-tree
0333-largest-bst-subtree
0538-convert-bst-to-greater-tree
0543-diameter-of-binary-tree
0663-equal-tree-partition
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree
1484-linked-list-in-binary-tree
2306-create-binary-tree-from-descriptions
3307-find-the-maximum-sum-of-node-values

Depth-First Search

0144-binary-tree-preorder-traversal
0302-smallest-rectangle-enclosing-black-pixels
0333-largest-bst-subtree
0386-lexicographical-numbers
0538-convert-bst-to-greater-tree
0543-diameter-of-binary-tree
0663-equal-tree-partition
0801-is-graph-bipartite
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1484-linked-list-in-binary-tree
2438-find-closest-node-to-given-two-nodes

Binary Search Tree

0255-verify-preorder-sequence-in-binary-search-tree
0333-largest-bst-subtree
0538-convert-bst-to-greater-tree
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree

Binary Tree

0144-binary-tree-preorder-traversal
0255-verify-preorder-sequence-in-binary-search-tree
0333-largest-bst-subtree
0538-convert-bst-to-greater-tree
0543-diameter-of-binary-tree
0663-equal-tree-partition
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree
1484-linked-list-in-binary-tree
2306-create-binary-tree-from-descriptions

Sliding Window

0003-longest-substring-without-repeating-characters
0187-repeated-dna-sequences
0487-max-consecutive-ones-ii
0594-longest-harmonious-subsequence
1084-find-k-length-substrings-with-no-repeated-characters
1138-grumpy-bookstore-owner
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
2003-distinct-numbers-in-each-subarray
2255-minimum-swaps-to-group-all-1s-together-ii
2394-count-subarrays-with-score-less-than-k
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2527-count-subarrays-with-fixed-bounds
3463-alternating-groups-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Prefix Sum

0325-maximum-size-subarray-sum-equals-k
0525-contiguous-array
0560-subarray-sum-equals-k
1370-count-number-of-nice-subarrays
1631-number-of-sub-arrays-with-odd-sum
2006-find-the-student-that-will-replace-the-chalk
2394-count-subarrays-with-score-less-than-k
2915-count-of-interesting-subarrays
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3643-zero-array-transformation-ii

Queue

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1951-find-the-winner-of-the-circular-game
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Ordered Set

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1903-design-most-recently-used-queue
2434-design-a-number-container-system

Monotonic Queue

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Graph

0801-is-graph-bipartite
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
1916-find-center-of-star-graph
2171-second-minimum-time-to-reach-destination
2379-maximum-total-importance-of-roads
2438-find-closest-node-to-given-two-nodes

Breadth-First Search

0302-smallest-rectangle-enclosing-black-pixels
0317-shortest-distance-from-all-buildings
0801-is-graph-bipartite
1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph
2171-second-minimum-time-to-reach-destination

Topological Sort

1431-all-ancestors-of-a-node-in-a-directed-acyclic-graph

Enumeration

1656-count-good-triplets
3469-maximum-height-of-a-triangle
3683-find-the-lexicographically-largest-string-from-the-box-i

Simulation

0054-spiral-matrix
0059-spiral-matrix-ii
0735-asteroid-collision
0906-walking-robot-simulation
1642-water-bottles
1803-average-waiting-time
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2021-remove-all-occurrences-of-a-substring
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2299-merge-nodes-in-between-zeros
2411-spiral-matrix-iv
2551-apply-operations-to-an-array
2645-pass-the-pillow
3332-minimum-operations-to-exceed-threshold-value-ii
3434-find-the-number-of-distinct-colors-among-the-balls
3447-clear-digits

Stack

0020-valid-parentheses
0042-trapping-rain-water
0144-binary-tree-preorder-traversal
0255-verify-preorder-sequence-in-binary-search-tree
0496-next-greater-element-i
0735-asteroid-collision
1903-design-most-recently-used-queue
2021-remove-all-occurrences-of-a-substring
3447-clear-digits

Dynamic Programming

0005-longest-palindromic-substring
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0264-ugly-number-ii
0300-longest-increasing-subsequence
0333-largest-bst-subtree
0416-partition-equal-subset-sum
0487-max-consecutive-ones-ii
0650-2-keys-keyboard
1013-fibonacci-number
1170-shortest-common-supersequence
1511-count-number-of-teams
1631-number-of-sub-arrays-with-odd-sum
1849-maximum-absolute-sum-of-any-subarray
2061-painting-a-grid-with-three-different-colors
2415-count-the-number-of-ideal-arrays
3307-find-the-maximum-sum-of-node-values
3490-find-the-maximum-length-of-valid-subsequence-i

Merge Sort

0023-merge-k-sorted-lists

Backtracking

0017-letter-combinations-of-a-phone-number
0040-combination-sum-ii
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
2802-find-the-punishment-number-of-an-integer

Binary Indexed Tree

1511-count-number-of-teams
1903-design-most-recently-used-queue

Segment Tree

1511-count-number-of-teams

Shortest Path

2171-second-minimum-time-to-reach-destination

Matrix

0048-rotate-image
0054-spiral-matrix
0059-spiral-matrix-ii
0073-set-matrix-zeroes
0302-smallest-rectangle-enclosing-black-pixels
0317-shortest-distance-from-all-buildings
2132-convert-1d-array-into-2d-array
2411-spiral-matrix-iv
3227-find-missing-and-repeated-values

Memoization

1013-fibonacci-number

Interactive

2875-count-houses-in-a-circular-street

Brainteaser

2644-bitwise-or-of-all-subsequence-sums

Union Find

0128-longest-consecutive-sequence
0801-is-graph-bipartite

Number Theory

2415-count-the-number-of-ideal-arrays
2610-closest-prime-numbers-in-range
2903-insert-greatest-common-divisors-in-linked-list

Rolling Hash

0187-repeated-dna-sequences

Hash Function

0187-repeated-dna-sequences

Database

1179-game-play-analysis-i
1180-game-play-analysis-ii

Design

0380-insert-delete-getrandom-o1
1903-design-most-recently-used-queue
2434-design-a-number-container-system

Combinatorics

2415-count-the-number-of-ideal-arrays
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Randomized

0380-insert-delete-getrandom-o1

Trie

0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order

Monotonic Stack

0042-trapping-rain-water
0255-verify-preorder-sequence-in-binary-search-tree
0496-next-greater-element-i