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

LeetCode Topics

String

0003-longest-substring-without-repeating-characters
0008-string-to-integer-atoi
0014-longest-common-prefix
0049-group-anagrams
0115-distinct-subsequences
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0257-binary-tree-paths
0424-longest-repeating-character-replacement
0451-sort-characters-by-frequency
0516-longest-palindromic-subsequence
0583-delete-operation-for-two-strings
0768-partition-labels
0812-rotate-string
1058-lexicographically-smallest-equivalent-string
1078-remove-outermost-parentheses
1170-shortest-common-supersequence
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1460-number-of-substrings-containing-all-three-characters
1473-find-the-longest-substring-containing-vowels-in-even-counts
1737-maximum-nesting-depth-of-the-parentheses
1890-sum-of-beauty-of-all-substrings
2032-largest-odd-number-in-string
2220-find-all-possible-recipes-from-given-supplies
2237-longest-palindrome-by-concatenating-two-letter-words
2463-minimum-recolors-to-get-k-consecutive-black-blocks
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3453-generate-binary-strings-without-adjacent-zeros
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

Dynamic Programming

0062-unique-paths
0070-climbing-stairs
0115-distinct-subsequences
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0152-maximum-product-subarray
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0300-longest-increasing-subsequence
0322-coin-change
0416-partition-equal-subset-sum
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0583-delete-operation-for-two-strings
0806-domino-and-tromino-tiling
0905-length-of-longest-fibonacci-subsequence
1170-shortest-common-supersequence
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1631-number-of-sub-arrays-with-odd-sum
1849-maximum-absolute-sum-of-any-subarray
1986-largest-color-value-in-a-directed-graph
2061-painting-a-grid-with-three-different-colors
2090-number-of-ways-to-arrive-at-destination
2262-solving-questions-with-brainpower
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations

Array

0001-two-sum
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0037-sudoku-solver
0039-combination-sum
0048-rotate-image
0049-group-anagrams
0051-n-queens
0054-spiral-matrix
0056-merge-intervals
0073-set-matrix-zeroes
0075-sort-colors
0078-subsets
0081-search-in-rotated-sorted-array-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0136-single-number
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0188-best-time-to-buy-and-sell-stock-iv
0189-rotate-array
0198-house-robber
0204-count-primes
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0238-product-of-array-except-self
0268-missing-number
0283-move-zeroes
0300-longest-increasing-subsequence
0303-range-sum-query-immutable
0322-coin-change
0416-partition-equal-subset-sum
0494-target-sum
0496-next-greater-element-i
0503-next-greater-element-ii
0518-coin-change-ii
0525-contiguous-array
0540-single-element-in-a-sorted-array
0735-asteroid-collision
0792-binary-search
0797-rabbits-in-forest
0905-length-of-longest-fibonacci-subsequence
0907-koko-eating-bananas
0945-snakes-and-ladders
0966-binary-subarrays-with-sum
1036-rotting-oranges
1046-max-consecutive-ones-iii
1049-minimum-domino-rotations-for-equal-row
1056-capacity-to-ship-packages-within-d-days
1206-corporate-flight-bookings
1227-number-of-equivalent-domino-pairs
1293-three-consecutive-odds
1335-maximum-candies-allocated-to-k-children
1408-find-the-smallest-divisor-given-a-threshold
1421-find-numbers-with-even-number-of-digits
1424-maximum-candies-you-can-get-from-boxes
1603-running-sum-of-1d-array
1605-minimum-number-of-days-to-make-m-bouquets
1631-number-of-sub-arrays-with-odd-sum
1646-kth-missing-positive-number
1833-find-the-highest-altitude
1849-maximum-absolute-sum-of-any-subarray
1993-sum-of-all-subset-xor-totals
2048-build-array-from-permutation
2102-find-the-middle-index-in-array
2160-minimum-operations-to-make-a-uni-value-grid
2215-finding-3-digit-even-numbers
2220-find-all-possible-recipes-from-given-supplies
2237-longest-palindrome-by-concatenating-two-letter-words
2262-solving-questions-with-brainpower
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2308-divide-array-into-equal-pairs
2358-number-of-ways-to-split-array
2478-longest-nice-subarray
2527-count-subarrays-with-fixed-bounds
2551-apply-operations-to-an-array
2588-maximum-number-of-points-from-grid-queries
2614-maximum-count-of-positive-integer-and-negative-integer
2626-count-the-number-of-good-subarrays
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
2856-count-complete-subarrays-in-an-array
2888-minimum-index-of-a-valid-split
2915-count-of-interesting-subarrays
3001-apply-operations-to-maximize-score
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3227-find-missing-and-repeated-values
3321-type-of-triangle
3430-count-days-without-meetings
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3621-minimum-operations-to-make-array-values-equal-to-k
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3657-check-if-grid-can-be-cut-into-sections
3685-count-subarrays-of-length-three-with-a-condition

Greedy

0122-best-time-to-buy-and-sell-stock-ii
0768-partition-labels
0797-rabbits-in-forest
1049-minimum-domino-rotations-for-equal-row
2032-largest-odd-number-in-string
2237-longest-palindrome-by-concatenating-two-letter-words
2681-put-marbles-in-bags
3001-apply-operations-to-maximize-score
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3647-zero-array-transformation-iii

Stack

0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0234-palindrome-linked-list
0496-next-greater-element-i
0503-next-greater-element-ii
0735-asteroid-collision
1078-remove-outermost-parentheses
1737-maximum-nesting-depth-of-the-parentheses
3001-apply-operations-to-maximize-score

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
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
0112-path-sum
0113-path-sum-ii
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0437-path-sum-iii
0662-maximum-width-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
2384-root-equals-sum-of-children
2461-amount-of-time-for-binary-tree-to-be-infected
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Depth-First Search

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0437-path-sum-iii
0662-maximum-width-of-binary-tree
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
2461-amount-of-time-for-binary-tree-to-be-infected
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
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
0112-path-sum
0113-path-sum-ii
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0437-path-sum-iii
0662-maximum-width-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0893-all-nodes-distance-k-in-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
2384-root-equals-sum-of-children
2461-amount-of-time-for-binary-tree-to-be-infected

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
0199-binary-tree-right-side-view
0322-coin-change
0662-maximum-width-of-binary-tree
0893-all-nodes-distance-k-in-binary-tree
0945-snakes-and-ladders
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1218-lowest-common-ancestor-of-deepest-leaves
1424-maximum-candies-you-can-get-from-boxes
2461-amount-of-time-for-binary-tree-to-be-infected
2588-maximum-number-of-points-from-grid-queries
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0037-sudoku-solver
0049-group-anagrams
0073-set-matrix-zeroes
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0205-isomorphic-strings
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0424-longest-repeating-character-replacement
0451-sort-characters-by-frequency
0496-next-greater-element-i
0525-contiguous-array
0768-partition-labels
0797-rabbits-in-forest
0893-all-nodes-distance-k-in-binary-tree
0905-length-of-longest-fibonacci-subsequence
0966-binary-subarrays-with-sum
1029-vertical-order-traversal-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1460-number-of-substrings-containing-all-three-characters
1473-find-the-longest-substring-containing-vowels-in-even-counts
1500-count-largest-group
1890-sum-of-beauty-of-all-substrings
1986-largest-color-value-in-a-directed-graph
2215-finding-3-digit-even-numbers
2220-find-all-possible-recipes-from-given-supplies
2237-longest-palindrome-by-concatenating-two-letter-words
2308-divide-array-into-equal-pairs
2461-amount-of-time-for-binary-tree-to-be-infected
2626-count-the-number-of-good-subarrays
2707-merge-two-2d-arrays-by-summing-values
2856-count-complete-subarrays-in-an-array
2888-minimum-index-of-a-valid-split
2915-count-of-interesting-subarrays
3227-find-missing-and-repeated-values
3621-minimum-operations-to-make-array-values-equal-to-k
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii

Sorting

0015-3sum
0018-4sum
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0169-majority-element
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0451-sort-characters-by-frequency
1029-vertical-order-traversal-of-a-binary-tree
2160-minimum-operations-to-make-a-uni-value-grid
2215-finding-3-digit-even-numbers
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
2699-count-the-number-of-fair-pairs
2888-minimum-index-of-a-valid-split
3001-apply-operations-to-maximize-score
3321-type-of-triangle
3430-count-days-without-meetings
3647-zero-array-transformation-iii
3657-check-if-grid-can-be-cut-into-sections

Binary Search Tree

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
0098-validate-binary-search-tree
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0268-missing-number
0300-longest-increasing-subsequence
0540-single-element-in-a-sorted-array
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0792-binary-search
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1335-maximum-candies-allocated-to-k-children
1408-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
2280-count-good-triplets-in-an-array
2614-maximum-count-of-positive-integer-and-negative-integer
2665-minimum-time-to-repair-cars
2699-count-the-number-of-fair-pairs

Matrix

0037-sudoku-solver
0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0945-snakes-and-ladders
1036-rotting-oranges
2160-minimum-operations-to-make-a-uni-value-grid
2588-maximum-number-of-points-from-grid-queries
3227-find-missing-and-repeated-values
3628-find-minimum-time-to-reach-last-room-ii

Monotonic Stack

0496-next-greater-element-i
0503-next-greater-element-ii
3001-apply-operations-to-maximize-score

Simulation

0054-spiral-matrix
0735-asteroid-collision
2048-build-array-from-permutation
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2551-apply-operations-to-an-array

Sliding Window

0003-longest-substring-without-repeating-characters
0424-longest-repeating-character-replacement
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1460-number-of-substrings-containing-all-three-characters
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2478-longest-nice-subarray
2527-count-subarrays-with-fixed-bounds
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Prefix Sum

0238-product-of-array-except-self
0303-range-sum-query-immutable
0525-contiguous-array
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1206-corporate-flight-bookings
1473-find-the-longest-substring-containing-vowels-in-even-counts
1603-running-sum-of-1d-array
1631-number-of-sub-arrays-with-odd-sum
1833-find-the-highest-altitude
2102-find-the-middle-index-in-array
2358-number-of-ways-to-split-array
2915-count-of-interesting-subarrays
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3639-zero-array-transformation-i
3647-zero-array-transformation-iii

Bit Manipulation

0078-subsets
0136-single-number
0222-count-complete-tree-nodes
0268-missing-number
1473-find-the-longest-substring-containing-vowels-in-even-counts
1993-sum-of-all-subset-xor-totals
2308-divide-array-into-equal-pairs
2478-longest-nice-subarray
3453-generate-binary-strings-without-adjacent-zeros
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Divide and Conquer

0105-construct-binary-tree-from-preorder-and-inorder-traversal
0169-majority-element
0215-kth-largest-element-in-an-array
2280-count-good-triplets-in-an-array

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0451-sort-characters-by-frequency
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii

Quickselect

0215-kth-largest-element-in-an-array

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
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
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list

Two Pointers

0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0075-sort-colors
0141-linked-list-cycle
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0768-partition-labels
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2551-apply-operations-to-an-array
2588-maximum-number-of-points-from-grid-queries
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3683-find-the-lexicographically-largest-string-from-the-box-i

Recursion

0002-add-two-numbers
0050-powx-n
0206-reverse-linked-list
0234-palindrome-linked-list
2050-count-good-numbers

Math

0002-add-two-numbers
0048-rotate-image
0050-powx-n
0062-unique-paths
0070-climbing-stairs
0189-rotate-array
0204-count-primes
0268-missing-number
0797-rabbits-in-forest
1421-find-numbers-with-even-number-of-digits
1500-count-largest-group
1631-number-of-sub-arrays-with-odd-sum
1889-check-if-number-is-a-sum-of-powers-of-three
1993-sum-of-all-subset-xor-totals
2032-largest-odd-number-in-string
2050-count-good-numbers
2160-minimum-operations-to-make-a-uni-value-grid
2610-closest-prime-numbers-in-range
2649-count-total-number-of-colored-cells
3001-apply-operations-to-maximize-score
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3227-find-missing-and-repeated-values
3321-type-of-triangle
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations

Design

0146-lru-cache
0303-range-sum-query-immutable

Doubly-Linked List

0146-lru-cache

Trie

0014-longest-common-prefix

String Matching

0812-rotate-string

Bucket Sort

0451-sort-characters-by-frequency

Counting

0169-majority-element
0229-majority-element-ii
0451-sort-characters-by-frequency
1227-number-of-equivalent-domino-pairs
1890-sum-of-beauty-of-all-substrings
1986-largest-color-value-in-a-directed-graph
2237-longest-palindrome-by-concatenating-two-letter-words
2308-divide-array-into-equal-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii

Backtracking

0037-sudoku-solver
0039-combination-sum
0051-n-queens
0078-subsets
0113-path-sum-ii
0257-binary-tree-paths
0494-target-sum
1993-sum-of-all-subset-xor-totals
3453-generate-binary-strings-without-adjacent-zeros

Enumeration

0204-count-primes
1993-sum-of-all-subset-xor-totals
2215-finding-3-digit-even-numbers
3201-distribute-candies-among-children-ii
3683-find-the-lexicographically-largest-string-from-the-box-i

Number Theory

0204-count-primes
2610-closest-prime-numbers-in-range
3001-apply-operations-to-maximize-score

Memoization

0070-climbing-stairs
1986-largest-color-value-in-a-directed-graph

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals
3201-distribute-candies-among-children-ii
3637-count-number-of-balanced-permutations

Queue

2527-count-subarrays-with-fixed-bounds
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Graph

1424-maximum-candies-you-can-get-from-boxes
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
3628-find-minimum-time-to-reach-last-room-ii

Topological Sort

1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies

Shortest Path

2090-number-of-ways-to-arrive-at-destination
3628-find-minimum-time-to-reach-last-room-ii

Union Find

1058-lexicographically-smallest-equivalent-string
2588-maximum-number-of-points-from-grid-queries

Binary Indexed Tree

2280-count-good-triplets-in-an-array

Segment Tree

2280-count-good-triplets-in-an-array

Merge Sort

2280-count-good-triplets-in-an-array

Ordered Set

2280-count-good-triplets-in-an-array

Monotonic Queue

2527-count-subarrays-with-fixed-bounds