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

LeetCode Topics

Tree

0103-binary-tree-zigzag-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0226-invert-binary-tree
0589-n-ary-tree-preorder-traversal
0590-n-ary-tree-postorder-traversal
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
2583-kth-largest-sum-in-a-binary-tree
2872-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees

Binary Search Tree

0004-median-of-two-sorted-arrays
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0162-find-peak-element
0410-split-array-largest-sum
0540-single-element-in-a-sorted-array
0611-valid-triangle-number
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0875-koko-eating-bananas
0887-super-egg-drop
1011-capacity-to-ship-packages-within-d-days
1283-find-the-smallest-divisor-given-a-threshold
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1482-minimum-number-of-days-to-make-m-bouquets
1539-kth-missing-positive-number
1552-magnetic-force-between-two-balls
1612-avoid-flood-in-the-city
1901-find-a-peak-element-ii
2047-find-a-peak-element-ii
2498-smallest-subarrays-with-maximum-bitwise-or
2616-minimize-the-maximum-difference-of-pairs
3437-maximum-total-damage-with-spell-casting
3982-maximum-walls-destroyed-by-robots

Binary Tree

0103-binary-tree-zigzag-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0116-populating-next-right-pointers-in-each-node
0144-binary-tree-preorder-traversal
0226-invert-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
2583-kth-largest-sum-in-a-binary-tree

Hash Table

0001-two-sum
0017-letter-combinations-of-a-phone-number
0041-first-missing-positive
0073-set-matrix-zeroes
0127-word-ladder
0139-word-break
0140-word-break-ii
0146-lru-cache
0187-repeated-dna-sequences
0208-implement-trie-prefix-tree
0355-design-twitter
0383-ransom-note
0387-first-unique-character-in-a-string
0421-maximum-xor-of-two-numbers-in-an-array
0491-non-decreasing-subsequences
0523-continuous-subarray-sum
0535-encode-and-decode-tinyurl
0648-replace-words
0705-design-hashset
0753-open-the-lock
1006-vowel-spellchecker
1048-longest-string-chain
1160-letter-tile-possibilities
1612-avoid-flood-in-the-city
1715-split-a-string-into-the-max-number-of-unique-substrings
2174-next-greater-numerically-balanced-number
2696-the-number-of-beautiful-subsets
2975-maximum-square-area-by-removing-fences-from-a-field
3329-find-the-length-of-the-longest-common-prefix
3437-maximum-total-damage-with-spell-casting
3493-properties-graph
3713-longest-balanced-substring-i
3714-longest-balanced-substring-ii
3737-count-subarrays-with-majority-element-i
3795-minimum-subarray-length-with-distinct-sum-at-least-k

String

0010-regular-expression-matching
0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0044-wildcard-matching
0072-edit-distance
0093-restore-ip-addresses
0115-distinct-subsequences
0127-word-ladder
0131-palindrome-partitioning
0139-word-break
0140-word-break-ii
0187-repeated-dna-sequences
0208-implement-trie-prefix-tree
0212-word-search-ii
0282-expression-add-operators
0383-ransom-note
0387-first-unique-character-in-a-string
0392-is-subsequence
0516-longest-palindromic-subsequence
0535-encode-and-decode-tinyurl
0583-delete-operation-for-two-strings
0648-replace-words
0753-open-the-lock
0944-delete-columns-to-make-sorted
1006-vowel-spellchecker
1048-longest-string-chain
1160-letter-tile-possibilities
1170-shortest-common-supersequence
1250-longest-common-subsequence
1381-maximum-score-words-formed-by-letters
1653-minimum-deletions-to-make-string-balanced
1700-minimum-time-to-make-rope-colorful
1715-split-a-string-into-the-max-number-of-unique-substrings
2137-final-value-of-variable-after-performing-operations
2211-count-collisions-on-a-road
2244-number-of-laser-beams-in-a-bank
2414-move-pieces-to-obtain-a-string
2494-sum-of-prefix-scores-of-strings
3230-remove-adjacent-almost-equal-characters
3329-find-the-length-of-the-longest-common-prefix
3376-longest-common-suffix-queries
3713-longest-balanced-substring-i
3714-longest-balanced-substring-ii

Queue

0387-first-unique-character-in-a-string
0954-maximum-sum-circular-subarray
2408-number-of-people-aware-of-a-secret

Counting

0383-ransom-note
0387-first-unique-character-in-a-string
1160-letter-tile-possibilities
2174-next-greater-numerically-balanced-number
2494-sum-of-prefix-scores-of-strings
3437-maximum-total-damage-with-spell-casting
3713-longest-balanced-substring-i
3737-count-subarrays-with-majority-element-i

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0031-next-permutation
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0039-combination-sum
0040-combination-sum-ii
0041-first-missing-positive
0046-permutations
0047-permutations-ii
0053-maximum-subarray
0056-merge-intervals
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0085-maximal-rectangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0130-surrounded-regions
0135-candy
0139-word-break
0140-word-break-ii
0162-find-peak-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0212-word-search-ii
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0368-largest-divisible-subset
0377-combination-sum-iv
0403-frog-jump
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0421-maximum-xor-of-two-numbers-in-an-array
0491-non-decreasing-subsequences
0494-target-sum
0498-diagonal-traverse
0518-coin-change-ii
0523-continuous-subarray-sum
0540-single-element-in-a-sorted-array
0542-01-matrix
0565-array-nesting
0611-valid-triangle-number
0648-replace-words
0673-number-of-longest-increasing-subsequence
0695-max-area-of-island
0705-design-hashset
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0753-open-the-lock
0875-koko-eating-bananas
0944-delete-columns-to-make-sorted
0954-maximum-sum-circular-subarray
0967-minimum-falling-path-sum
0994-rotting-oranges
1006-vowel-spellchecker
1011-capacity-to-ship-packages-within-d-days
1022-unique-paths-iii
1036-rotting-oranges
1048-longest-string-chain
1073-number-of-enclaves
1277-count-square-submatrices-with-all-ones
1283-find-the-smallest-divisor-given-a-threshold
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1381-maximum-score-words-formed-by-letters
1390-four-divisors
1426-find-n-unique-integers-sum-up-to-zero
1482-minimum-number-of-days-to-make-m-bouquets
1539-kth-missing-positive-number
1552-magnetic-force-between-two-balls
1612-avoid-flood-in-the-city
1700-minimum-time-to-make-rope-colorful
1723-maximum-number-of-achievable-transfer-requests
1819-construct-the-lexicographically-largest-valid-sequence
1876-map-of-highest-peak
1877-minimize-maximum-pair-sum-in-array
1895-largest-magic-square
1901-find-a-peak-element-ii
1975-maximum-matrix-sum
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2016-reduction-operations-to-make-the-array-elements-equal
2047-find-a-peak-element-ii
2104-sum-of-subarray-ranges
2137-final-value-of-variable-after-performing-operations
2244-number-of-laser-beams-in-a-bank
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2494-sum-of-prefix-scores-of-strings
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2616-minimize-the-maximum-difference-of-pairs
2696-the-number-of-beautiful-subsets
2761-prime-pairs-with-target-sum
2943-maximize-area-of-square-hole-in-grid
2975-maximum-square-area-by-removing-fences-from-a-field
3277-find-the-number-of-ways-to-place-people-ii
3315-construct-the-minimum-bitwise-array-ii
3329-find-the-length-of-the-longest-common-prefix
3376-longest-common-suffix-queries
3431-find-the-minimum-cost-array-permutation
3437-maximum-total-damage-with-spell-casting
3493-properties-graph
3737-count-subarrays-with-majority-element-i
3795-minimum-subarray-length-with-distinct-sum-at-least-k
3982-maximum-walls-destroyed-by-robots

Sorting

0047-permutations-ii
0056-merge-intervals
0148-sort-list
0368-largest-divisible-subset
0611-valid-triangle-number
1048-longest-string-chain
1552-magnetic-force-between-two-balls
1877-minimize-maximum-pair-sum-in-array
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2016-reduction-operations-to-make-the-array-elements-equal
2583-kth-largest-sum-in-a-binary-tree
2616-minimize-the-maximum-difference-of-pairs
2696-the-number-of-beautiful-subsets
2943-maximize-area-of-square-hole-in-grid
3277-find-the-number-of-ways-to-place-people-ii
3437-maximum-total-damage-with-spell-casting
3982-maximum-walls-destroyed-by-robots

Dynamic Programming

0010-regular-expression-matching
0022-generate-parentheses
0044-wildcard-matching
0053-maximum-subarray
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0085-maximal-rectangle
0115-distinct-subsequences
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0131-palindrome-partitioning
0139-word-break
0140-word-break-ii
0198-house-robber
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0368-largest-divisible-subset
0377-combination-sum-iv
0392-is-subsequence
0403-frog-jump
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0542-01-matrix
0583-delete-operation-for-two-strings
0673-number-of-longest-increasing-subsequence
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0887-super-egg-drop
0954-maximum-sum-circular-subarray
0967-minimum-falling-path-sum
1048-longest-string-chain
1170-shortest-common-supersequence
1250-longest-common-subsequence
1277-count-square-submatrices-with-all-ones
1381-maximum-score-words-formed-by-letters
1411-number-of-ways-to-paint-n-3-grid
1653-minimum-deletions-to-make-string-balanced
1700-minimum-time-to-make-rope-colorful
1931-painting-a-grid-with-three-different-colors
2408-number-of-people-aware-of-a-secret
2616-minimize-the-maximum-difference-of-pairs
2696-the-number-of-beautiful-subsets
3230-remove-adjacent-almost-equal-characters
3431-find-the-minimum-cost-array-permutation
3437-maximum-total-damage-with-spell-casting
3982-maximum-walls-destroyed-by-robots

Greedy

0044-wildcard-matching
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0410-split-array-largest-sum
0611-valid-triangle-number
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
1612-avoid-flood-in-the-city
1700-minimum-time-to-make-rope-colorful
1877-minimize-maximum-pair-sum-in-array
1975-maximum-matrix-sum
2616-minimize-the-maximum-difference-of-pairs
3230-remove-adjacent-almost-equal-characters

Two Pointers

0031-next-permutation
0082-remove-duplicates-from-sorted-list-ii
0148-sort-list
0189-rotate-array
0392-is-subsequence
0611-valid-triangle-number
1048-longest-string-chain
1877-minimize-maximum-pair-sum-in-array
2414-move-pieces-to-obtain-a-string
3437-maximum-total-damage-with-spell-casting

Depth-First Search

0116-populating-next-right-pointers-in-each-node
0130-surrounded-regions
0144-binary-tree-preorder-traversal
0200-number-of-islands
0207-course-schedule
0226-invert-binary-tree
0547-number-of-provinces
0565-array-nesting
0589-n-ary-tree-preorder-traversal
0590-n-ary-tree-postorder-traversal
0695-max-area-of-island
0820-find-eventual-safe-states
1073-number-of-enclaves
1161-maximum-level-sum-of-a-binary-tree
1339-maximum-product-of-splitted-binary-tree
2872-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees
3493-properties-graph

Breadth-First Search

0103-binary-tree-zigzag-level-order-traversal
0107-binary-tree-level-order-traversal-ii
0116-populating-next-right-pointers-in-each-node
0127-word-ladder
0130-surrounded-regions
0200-number-of-islands
0207-course-schedule
0226-invert-binary-tree
0542-01-matrix
0547-number-of-provinces
0695-max-area-of-island
0753-open-the-lock
0820-find-eventual-safe-states
0994-rotting-oranges
1036-rotting-oranges
1073-number-of-enclaves
1161-maximum-level-sum-of-a-binary-tree
1876-map-of-highest-peak
2583-kth-largest-sum-in-a-binary-tree
3439-find-minimum-diameter-after-merging-two-trees
3493-properties-graph

Stack

0085-maximal-rectangle
0144-binary-tree-preorder-traversal
0589-n-ary-tree-preorder-traversal
0590-n-ary-tree-postorder-traversal
1653-minimum-deletions-to-make-string-balanced
2104-sum-of-subarray-ranges
2211-count-collisions-on-a-road
2307-replace-non-coprime-numbers-in-array

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0148-sort-list
0190-reverse-bits
0954-maximum-sum-circular-subarray
3737-count-subarrays-with-majority-element-i

Bit Manipulation

0187-repeated-dna-sequences
0190-reverse-bits
0421-maximum-xor-of-two-numbers-in-an-array
0491-non-decreasing-subsequences
0868-binary-gap
1022-unique-paths-iii
1381-maximum-score-words-formed-by-letters
1723-maximum-number-of-achievable-transfer-requests
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
3315-construct-the-minimum-bitwise-array-ii
3431-find-the-minimum-cost-array-permutation

Sliding Window

0187-repeated-dna-sequences
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2498-smallest-subarrays-with-maximum-bitwise-or
3795-minimum-subarray-length-with-distinct-sum-at-least-k

Brainteaser

2503-longest-subarray-with-maximum-bitwise-and

Union Find

0130-surrounded-regions
0547-number-of-provinces
1073-number-of-enclaves

Graph

0207-course-schedule
0547-number-of-provinces
0820-find-eventual-safe-states
3439-find-minimum-diameter-after-merging-two-trees

Topological Sort

0207-course-schedule
0820-find-eventual-safe-states

Math

0062-unique-paths
0070-climbing-stairs
0189-rotate-array
0282-expression-add-operators
0368-largest-divisible-subset
0523-continuous-subarray-sum
0887-super-egg-drop
1390-four-divisors
1426-find-n-unique-integers-sum-up-to-zero
1642-water-bottles
2174-next-greater-numerically-balanced-number
2244-number-of-laser-beams-in-a-bank
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2696-the-number-of-beautiful-subsets
2761-prime-pairs-with-target-sum
3277-find-the-number-of-ways-to-place-people-ii
3336-water-bottles-ii

Geometry

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

Enumeration

1723-maximum-number-of-achievable-transfer-requests
2174-next-greater-numerically-balanced-number
2761-prime-pairs-with-target-sum
2975-maximum-square-area-by-removing-fences-from-a-field
3277-find-the-number-of-ways-to-place-people-ii
3713-longest-balanced-substring-i

Matrix

0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0085-maximal-rectangle
0130-surrounded-regions
0200-number-of-islands
0212-word-search-ii
0498-diagonal-traverse
0542-01-matrix
0695-max-area-of-island
0967-minimum-falling-path-sum
0994-rotting-oranges
1022-unique-paths-iii
1036-rotting-oranges
1073-number-of-enclaves
1277-count-square-submatrices-with-all-ones
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1876-map-of-highest-peak
1895-largest-magic-square
1901-find-a-peak-element-ii
1975-maximum-matrix-sum
2047-find-a-peak-element-ii
2244-number-of-laser-beams-in-a-bank

Simulation

0498-diagonal-traverse
1642-water-bottles
2137-final-value-of-variable-after-performing-operations
2211-count-collisions-on-a-road
2324-find-triangular-sum-of-an-array
2408-number-of-people-aware-of-a-secret
3336-water-bottles-ii

Design

0146-lru-cache
0208-implement-trie-prefix-tree
0355-design-twitter
0535-encode-and-decode-tinyurl
0705-design-hashset

Trie

0139-word-break
0140-word-break-ii
0208-implement-trie-prefix-tree
0212-word-search-ii
0421-maximum-xor-of-two-numbers-in-an-array
0648-replace-words
2494-sum-of-prefix-scores-of-strings
3329-find-the-length-of-the-longest-common-prefix
3376-longest-common-suffix-queries

Linked List

0023-merge-k-sorted-lists
0082-remove-duplicates-from-sorted-list-ii
0116-populating-next-right-pointers-in-each-node
0146-lru-cache
0148-sort-list
0355-design-twitter
0705-design-hashset

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0047-permutations-ii
0052-n-queens-ii
0077-combinations
0093-restore-ip-addresses
0131-palindrome-partitioning
0140-word-break-ii
0212-word-search-ii
0282-expression-add-operators
0491-non-decreasing-subsequences
0494-target-sum
1022-unique-paths-iii
1160-letter-tile-possibilities
1381-maximum-score-words-formed-by-letters
1715-split-a-string-into-the-max-number-of-unique-substrings
1723-maximum-number-of-achievable-transfer-requests
1819-construct-the-lexicographically-largest-valid-sequence
2174-next-greater-numerically-balanced-number
2696-the-number-of-beautiful-subsets

Number Theory

2307-replace-non-coprime-numbers-in-array
2761-prime-pairs-with-target-sum

Heap (Priority Queue)

0023-merge-k-sorted-lists
0355-design-twitter
1612-avoid-flood-in-the-city

Merge Sort

0023-merge-k-sorted-lists
0148-sort-list
3737-count-subarrays-with-majority-element-i

Bitmask

1381-maximum-score-words-formed-by-letters
3431-find-the-minimum-cost-array-permutation

Combinatorics

0062-unique-paths
2324-find-triangular-sum-of-an-array
2696-the-number-of-beautiful-subsets

Memoization

0070-climbing-stairs
0139-word-break
0140-word-break-ii

Hash Function

0187-repeated-dna-sequences
0535-encode-and-decode-tinyurl
0705-design-hashset

Monotonic Queue

0954-maximum-sum-circular-subarray

Recursion

0010-regular-expression-matching
0044-wildcard-matching

Monotonic Stack

0085-maximal-rectangle
2104-sum-of-subarray-ranges

Binary Indexed Tree

0673-number-of-longest-increasing-subsequence

Segment Tree

0673-number-of-longest-increasing-subsequence
3737-count-subarrays-with-majority-element-i

Prefix Sum

0410-split-array-largest-sum
0523-continuous-subarray-sum
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1895-largest-magic-square
3714-longest-balanced-substring-ii
3737-count-subarrays-with-majority-element-i

Union-Find

0200-number-of-islands
0695-max-area-of-island
3493-properties-graph

Graph Theory

0207-course-schedule
3493-properties-graph

Rolling Hash

0187-repeated-dna-sequences

Doubly-Linked List

0146-lru-cache