leetcode

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

Array

0056-merge-intervals
0075-sort-colors
0078-subsets
0216-combination-sum-iii
0380-insert-delete-getrandom-o1
0645-set-mismatch
0853-most-profit-assigning-work
1217-relative-sort-array
1319-unique-number-of-occurrences

Sorting

0056-merge-intervals
0075-sort-colors
0645-set-mismatch
0853-most-profit-assigning-work
1217-relative-sort-array

Tree

0832-binary-tree-pruning
1021-distribute-coins-in-binary-tree

Depth-First Search

0832-binary-tree-pruning
1021-distribute-coins-in-binary-tree

Binary Tree

0832-binary-tree-pruning
1021-distribute-coins-in-binary-tree

Backtracking

0078-subsets
0216-combination-sum-iii

Bit Manipulation

0078-subsets
0645-set-mismatch

Hash Table

0380-insert-delete-getrandom-o1
0645-set-mismatch
1217-relative-sort-array
1319-unique-number-of-occurrences

Counting Sort

1217-relative-sort-array

Two Pointers

0075-sort-colors
0633-sum-of-square-numbers
0853-most-profit-assigning-work

Math

0380-insert-delete-getrandom-o1
0633-sum-of-square-numbers

Design

0380-insert-delete-getrandom-o1

Randomized

0380-insert-delete-getrandom-o1

Binary Search

0633-sum-of-square-numbers
0853-most-profit-assigning-work

Greedy

0853-most-profit-assigning-work

LeetCode Topics

Array

0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0036-valid-sudoku
0041-first-missing-positive
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0059-spiral-matrix-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0075-sort-colors
0078-subsets
0079-word-search
0090-subsets-ii
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
0130-surrounded-regions
0136-single-number
0137-single-number-ii
0164-maximum-gap
0167-two-sum-ii-input-array-is-sorted
0179-largest-number
0188-best-time-to-buy-and-sell-stock-iv
0189-rotate-array
0198-house-robber
0200-number-of-islands
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0260-single-number-iii
0289-game-of-life
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0442-find-all-duplicates-in-an-array
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0474-ones-and-zeroes
0494-target-sum
0518-coin-change-ii
0526-beautiful-arrangement
0539-minimum-time-difference
0560-subarray-sum-equals-k
0621-task-scheduler
0697-degree-of-an-array
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0718-maximum-length-of-repeated-subarray
0719-find-k-th-smallest-pair-distance
0724-find-pivot-index
0739-daily-temperatures
0748-largest-number-at-least-twice-of-others
0792-binary-search
0797-rabbits-in-forest
0843-binary-trees-with-factors
0853-most-profit-assigning-work
0876-hand-of-straights
0890-lemonade-change
0892-shortest-subarray-with-sum-at-least-k
0902-minimum-number-of-refueling-stops
0905-length-of-longest-fibonacci-subsequence
0917-boats-to-save-people
0948-sort-an-array
0982-minimum-increment-to-make-array-unique
0983-validate-stack-sequences
0985-bag-of-tokens
1025-minimum-cost-for-tickets
1049-minimum-domino-rotations-for-equal-row
1227-number-of-equivalent-domino-pairs
1273-compare-strings-by-frequency-of-the-smallest-character
1293-three-consecutive-odds
1333-sort-the-jumbled-numbers
1396-count-servers-that-communicate
1421-find-numbers-with-even-number-of-digits
1422-divide-array-in-sets-of-k-consecutive-numbers
1463-the-k-weakest-rows-in-a-matrix
1468-check-if-n-and-its-double-exist
1477-product-of-the-last-k-numbers
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1497-design-a-stack-with-increment-operation
1511-count-number-of-teams
1524-string-matching-in-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1570-final-prices-with-a-special-discount-in-a-shop
1604-least-number-of-unique-integers-after-k-removals
1615-range-sum-of-sorted-subarray-sums
1620-check-if-array-pairs-are-divisible-by-k
1656-count-good-triplets
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1711-find-valid-matrix-given-row-and-column-sums
1720-crawler-log-folder
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1803-average-waiting-time
1878-check-if-array-is-sorted-and-rotated
1886-minimum-limit-of-balls-in-a-bag
1917-maximum-average-pass-ratio
1923-sentence-similarity-iii
1940-maximum-xor-for-each-query
1972-rotating-the-box
1993-sum-of-all-subset-xor-totals
2089-maximum-matrix-sum
2107-find-unique-binary-string
2148-minimum-number-of-moves-to-seat-everyone
2160-minimum-operations-to-make-a-uni-value-grid
2163-kth-distinct-string-in-an-array
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2232-adding-spaces-to-a-string
2237-longest-palindrome-by-concatenating-two-letter-words
2249-count-the-hidden-sequences
2262-solving-questions-with-brainpower
2265-partition-array-according-to-given-pivot
2277-count-equal-and-divisible-pairs-in-an-array
2292-counting-words-with-a-given-prefix
2355-maximum-consecutive-floors-without-special-floors
2356-largest-combination-with-bitwise-and-greater-than-zero
2358-number-of-ways-to-split-array
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2527-count-subarrays-with-fixed-bounds
2533-bitwise-xor-of-all-pairings
2552-maximum-sum-of-distinct-subarrays-with-length-k
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2673-maximize-win-from-two-segments
2691-count-vowel-strings-in-ranges
2695-find-score-of-an-array-after-marking-all-elements
2716-prime-subtraction-operation
2727-number-of-senior-citizens
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
2856-count-complete-subarrays-in-an-array
3106-length-of-the-longest-subsequence-that-sums-to-target
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
3262-find-polygon-with-the-largest-perimeter
3291-find-if-array-can-be-sorted
3307-find-the-maximum-sum-of-node-values
3309-count-prefix-and-suffix-pairs-i
3321-type-of-triangle
3351-maximize-happiness-of-selected-children
3380-shortest-subarray-with-or-at-least-k-ii
3434-find-the-number-of-distinct-colors-among-the-balls
3483-alternating-groups-ii
3490-find-the-maximum-length-of-valid-subsequence-i
3522-find-the-power-of-k-size-subarrays-i
3555-final-array-state-after-k-multiplication-operations-i
3621-minimum-operations-to-make-array-values-equal-to-k
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
3685-count-subarrays-of-length-three-with-a-condition

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0075-sort-colors
0125-valid-palindrome
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0234-palindrome-linked-list
0455-assign-cookies
0567-permutation-in-string
0719-find-k-th-smallest-pair-distance
0853-most-profit-assigning-work
0868-push-dominoes
0908-middle-of-the-linked-list
0917-boats-to-save-people
0953-reverse-only-letters
0985-bag-of-tokens
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1923-sentence-similarity-iii
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2216-delete-the-middle-node-of-a-linked-list
2232-adding-spaces-to-a-string
2265-partition-array-according-to-given-pivot
2581-divide-players-into-teams-of-equal-skill
3018-make-string-a-subsequence-using-cyclic-increments

Sorting

0015-3sum
0047-permutations-ii
0075-sort-colors
0164-maximum-gap
0179-largest-number
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0242-valid-anagram
0368-largest-divisible-subset
0451-sort-characters-by-frequency
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0539-minimum-time-difference
0621-task-scheduler
0719-find-k-th-smallest-pair-distance
0748-largest-number-at-least-twice-of-others
0807-custom-sort-string
0843-binary-trees-with-factors
0853-most-profit-assigning-work
0876-hand-of-straights
0917-boats-to-save-people
0948-sort-an-array
0982-minimum-increment-to-make-array-unique
0985-bag-of-tokens
1029-vertical-order-traversal-of-a-binary-tree
1273-compare-strings-by-frequency-of-the-smallest-character
1333-sort-the-jumbled-numbers
1422-divide-array-in-sets-of-k-consecutive-numbers
1463-the-k-weakest-rows-in-a-matrix
1468-check-if-n-and-its-double-exist
1556-make-two-arrays-equal-by-reversing-subarrays
1604-least-number-of-unique-integers-after-k-removals
1615-range-sum-of-sorted-subarray-sums
1741-sort-array-by-increasing-frequency
2148-minimum-number-of-moves-to-seat-everyone
2160-minimum-operations-to-make-a-uni-value-grid
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2355-maximum-consecutive-floors-without-special-floors
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2646-kth-largest-sum-in-a-binary-tree
2695-find-score-of-an-array-after-marking-all-elements
3262-find-polygon-with-the-largest-perimeter
3276-minimum-number-of-pushes-to-type-word-ii
3291-find-if-array-can-be-sorted
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3351-maximize-happiness-of-selected-children
3647-zero-array-transformation-iii

Tree

0094-binary-tree-inorder-traversal
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0515-find-largest-value-in-each-tree-row
0617-merge-two-binary-trees
0789-kth-largest-element-in-a-stream
0832-binary-tree-pruning
1008-binary-tree-cameras
1029-vertical-order-traversal-of-a-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree
3307-find-the-maximum-sum-of-node-values
3439-find-minimum-diameter-after-merging-two-trees
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

0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0130-surrounded-regions
0200-number-of-islands
0226-invert-binary-tree
0322-coin-change
0515-find-largest-value-in-each-tree-row
0547-number-of-provinces
0617-merge-two-binary-trees
0813-all-paths-from-source-to-target
1029-vertical-order-traversal-of-a-binary-tree
1396-count-servers-that-communicate
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree
3439-find-minimum-diameter-after-merging-two-trees
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
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0515-find-largest-value-in-each-tree-row
0617-merge-two-binary-trees
0789-kth-largest-element-in-a-stream
0832-binary-tree-pruning
1008-binary-tree-cameras
1029-vertical-order-traversal-of-a-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree

Design

0225-implement-stack-using-queues
0789-kth-largest-element-in-a-stream
1477-product-of-the-last-k-numbers
1497-design-a-stack-with-increment-operation
1955-seat-reservation-manager

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0264-ugly-number-ii
0451-sort-characters-by-frequency
0621-task-scheduler
0789-kth-largest-element-in-a-stream
0892-shortest-subarray-with-sum-at-least-k
0902-minimum-number-of-refueling-stops
0948-sort-an-array
1463-the-k-weakest-rows-in-a-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1917-maximum-average-pass-ratio
1955-seat-reservation-manager
2164-two-best-non-overlapping-events
2300-construct-string-with-repeat-limit
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2695-find-score-of-an-array-after-marking-all-elements
3445-lexicographically-minimum-string-after-removing-stars
3555-final-array-state-after-k-multiplication-operations-i
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii

Simulation

0043-multiply-strings
0054-spiral-matrix
0059-spiral-matrix-ii
0289-game-of-life
0983-validate-stack-sequences
1803-average-waiting-time
2021-remove-all-occurrences-of-a-substring
2232-adding-spaces-to-a-string
2265-partition-array-according-to-given-pivot
2695-find-score-of-an-array-after-marking-all-elements
2800-minimum-string-length-after-removing-substrings
3434-find-the-number-of-distinct-colors-among-the-balls
3555-final-array-state-after-k-multiplication-operations-i

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0008-string-to-integer-atoi
0022-generate-parentheses
0038-count-and-say
0043-multiply-strings
0044-wildcard-matching
0071-simplify-path
0072-edit-distance
0079-word-search
0097-interleaving-string
0115-distinct-subsequences
0125-valid-palindrome
0151-reverse-words-in-a-string
0179-largest-number
0242-valid-anagram
0387-first-unique-character-in-a-string
0423-reconstruct-original-digits-from-english
0451-sort-characters-by-frequency
0474-ones-and-zeroes
0516-longest-palindromic-subsequence
0539-minimum-time-difference
0567-permutation-in-string
0583-delete-operation-for-two-strings
0678-valid-parenthesis-string
0807-custom-sort-string
0812-rotate-string
0868-push-dominoes
0920-uncommon-words-from-two-sentences
0953-reverse-only-letters
1170-shortest-common-supersequence
1250-longest-common-subsequence
1273-compare-strings-by-frequency-of-the-smallest-character
1298-reverse-substrings-between-each-pair-of-parentheses
1321-get-equal-substrings-within-budget
1369-minimum-swaps-to-make-strings-equal
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
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1720-crawler-log-folder
1737-maximum-nesting-depth-of-the-parentheses
1786-count-the-number-of-consistent-strings
1890-sum-of-beauty-of-all-substrings
1923-sentence-similarity-iii
2021-remove-all-occurrences-of-a-substring
2059-unique-length-3-palindromic-subsequences
2095-minimum-number-of-swaps-to-make-the-string-balanced
2107-find-unique-binary-string
2149-remove-colored-pieces-if-both-neighbors-are-the-same-color
2163-kth-distinct-string-in-an-array
2221-check-if-a-parentheses-string-can-be-valid
2232-adding-spaces-to-a-string
2237-longest-palindrome-by-concatenating-two-letter-words
2292-counting-words-with-a-given-prefix
2300-construct-string-with-repeat-limit
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2502-sort-the-people
2599-take-k-of-each-character-from-left-and-right
2691-count-vowel-strings-in-ranges
2727-number-of-senior-citizens
2800-minimum-string-length-after-removing-substrings
3018-make-string-a-subsequence-using-cyclic-increments
3055-maximum-odd-binary-number
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3276-minimum-number-of-pushes-to-type-word-ii
3309-count-prefix-and-suffix-pairs-i
3445-lexicographically-minimum-string-after-removing-stars
3451-string-compression-iii
3455-minimum-length-of-string-after-operations
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations

Stack

0071-simplify-path
0094-binary-tree-inorder-traversal
0145-binary-tree-postorder-traversal
0225-implement-stack-using-queues
0234-palindrome-linked-list
0678-valid-parenthesis-string
0739-daily-temperatures
0983-validate-stack-sequences
1298-reverse-substrings-between-each-pair-of-parentheses
1497-design-a-stack-with-increment-operation
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1720-crawler-log-folder
1737-maximum-nesting-depth-of-the-parentheses
2021-remove-all-occurrences-of-a-substring
2095-minimum-number-of-swaps-to-make-the-string-balanced
2221-check-if-a-parentheses-string-can-be-valid
2800-minimum-string-length-after-removing-substrings
3445-lexicographically-minimum-string-after-removing-stars

Greedy

0011-container-with-most-water
0044-wildcard-matching
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0179-largest-number
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0621-task-scheduler
0670-maximum-swap
0678-valid-parenthesis-string
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0797-rabbits-in-forest
0853-most-profit-assigning-work
0876-hand-of-straights
0890-lemonade-change
0902-minimum-number-of-refueling-stops
0917-boats-to-save-people
0982-minimum-increment-to-make-array-unique
0985-bag-of-tokens
1049-minimum-domino-rotations-for-equal-row
1369-minimum-swaps-to-make-strings-equal
1422-divide-array-in-sets-of-k-consecutive-numbers
1502-construct-k-palindrome-strings
1604-least-number-of-unique-integers-after-k-removals
1711-find-valid-matrix-given-row-and-column-sums
1917-maximum-average-pass-ratio
2089-maximum-matrix-sum
2095-minimum-number-of-swaps-to-make-the-string-balanced
2148-minimum-number-of-moves-to-seat-everyone
2149-remove-colored-pieces-if-both-neighbors-are-the-same-color
2180-maximum-number-of-tasks-you-can-assign
2221-check-if-a-parentheses-string-can-be-valid
2237-longest-palindrome-by-concatenating-two-letter-words
2300-construct-string-with-repeat-limit
2509-minimize-xor
2640-maximum-number-of-integers-to-choose-from-a-range-i
2716-prime-subtraction-operation
3055-maximum-odd-binary-number
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3262-find-polygon-with-the-largest-perimeter
3276-minimum-number-of-pushes-to-type-word-ii
3307-find-the-maximum-sum-of-node-values
3351-maximize-happiness-of-selected-children
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii

Prefix Sum

0560-subarray-sum-equals-k
0724-find-pivot-index
0892-shortest-subarray-with-sum-at-least-k
1321-get-equal-substrings-within-budget
1473-find-the-longest-substring-containing-vowels-in-even-counts
1477-product-of-the-last-k-numbers
1940-maximum-xor-for-each-query
2059-unique-length-3-palindromic-subsequences
2249-count-the-hidden-sequences
2358-number-of-ways-to-split-array
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2691-count-vowel-strings-in-ranges
3262-find-polygon-with-the-largest-perimeter
3639-zero-array-transformation-i
3647-zero-array-transformation-iii

Matrix

0036-valid-sudoku
0054-spiral-matrix
0059-spiral-matrix-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0079-word-search
0130-surrounded-regions
0200-number-of-islands
0289-game-of-life
1396-count-servers-that-communicate
1463-the-k-weakest-rows-in-a-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1711-find-valid-matrix-given-row-and-column-sums
1972-rotating-the-box
2089-maximum-matrix-sum
2160-minimum-operations-to-make-a-uni-value-grid
3227-find-missing-and-repeated-values
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Hash Table

0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0041-first-missing-positive
0073-set-matrix-zeroes
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0217-contains-duplicate
0242-valid-anagram
0264-ugly-number-ii
0387-first-unique-character-in-a-string
0423-reconstruct-original-digits-from-english
0442-find-all-duplicates-in-an-array
0451-sort-characters-by-frequency
0560-subarray-sum-equals-k
0567-permutation-in-string
0621-task-scheduler
0697-degree-of-an-array
0797-rabbits-in-forest
0807-custom-sort-string
0843-binary-trees-with-factors
0876-hand-of-straights
0905-length-of-longest-fibonacci-subsequence
0920-uncommon-words-from-two-sentences
1029-vertical-order-traversal-of-a-binary-tree
1227-number-of-equivalent-domino-pairs
1273-compare-strings-by-frequency-of-the-smallest-character
1422-divide-array-in-sets-of-k-consecutive-numbers
1460-number-of-substrings-containing-all-three-characters
1468-check-if-n-and-its-double-exist
1473-find-the-longest-substring-containing-vowels-in-even-counts
1502-construct-k-palindrome-strings
1556-make-two-arrays-equal-by-reversing-subarrays
1604-least-number-of-unique-integers-after-k-removals
1620-check-if-array-pairs-are-divisible-by-k
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1890-sum-of-beauty-of-all-substrings
1986-largest-color-value-in-a-directed-graph
2059-unique-length-3-palindromic-subsequences
2107-find-unique-binary-string
2163-kth-distinct-string-in-an-array
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2300-construct-string-with-repeat-limit
2356-largest-combination-with-bitwise-and-greater-than-zero
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2552-maximum-sum-of-distinct-subarrays-with-length-k
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2599-take-k-of-each-character-from-left-and-right
2640-maximum-number-of-integers-to-choose-from-a-range-i
2695-find-score-of-an-array-after-marking-all-elements
2766-find-the-prefix-common-array-of-two-arrays
2856-count-complete-subarrays-in-an-array
3227-find-missing-and-repeated-values
3276-minimum-number-of-pushes-to-type-word-ii
3434-find-the-number-of-distinct-colors-among-the-balls
3445-lexicographically-minimum-string-after-removing-stars
3455-minimum-length-of-string-after-operations
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3629-total-characters-in-string-after-transformations-i

Database

0570-managers-with-at-least-5-direct-reports
0584-find-customer-referee
0595-big-countries
1258-article-views-i
1827-invalid-tweets
1908-recyclable-and-low-fat-products

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0191-number-of-1-bits
0215-kth-largest-element-in-an-array
0948-sort-an-array

Merge Sort

0948-sort-an-array

Bucket Sort

0164-maximum-gap
0451-sort-characters-by-frequency
0948-sort-an-array

Radix Sort

0164-maximum-gap
0948-sort-an-array

Counting Sort

0387-first-unique-character-in-a-string
0451-sort-characters-by-frequency
0621-task-scheduler
0920-uncommon-words-from-two-sentences
0948-sort-an-array
0982-minimum-increment-to-make-array-unique
1227-number-of-equivalent-domino-pairs
1396-count-servers-that-communicate
1502-construct-k-palindrome-strings
1604-least-number-of-unique-integers-after-k-removals
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
1890-sum-of-beauty-of-all-substrings
1986-largest-color-value-in-a-directed-graph
2148-minimum-number-of-moves-to-seat-everyone
2163-kth-distinct-string-in-an-array
2237-longest-palindrome-by-concatenating-two-letter-words
2300-construct-string-with-repeat-limit
2356-largest-combination-with-bitwise-and-greater-than-zero
3276-minimum-number-of-pushes-to-type-word-ii
3455-minimum-length-of-string-after-operations
3629-total-characters-in-string-after-transformations-i

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0044-wildcard-matching
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0097-interleaving-string
0115-distinct-subsequences
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
0124-binary-tree-maximum-path-sum
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0213-house-robber-ii
0264-ugly-number-ii
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0338-counting-bits
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0464-can-i-win
0474-ones-and-zeroes
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0526-beautiful-arrangement
0583-delete-operation-for-two-strings
0678-valid-parenthesis-string
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0718-maximum-length-of-repeated-subarray
0806-domino-and-tromino-tiling
0815-champagne-tower
0843-binary-trees-with-factors
0868-push-dominoes
0902-minimum-number-of-refueling-stops
0905-length-of-longest-fibonacci-subsequence
1008-binary-tree-cameras
1013-fibonacci-number
1025-minimum-cost-for-tickets
1170-shortest-common-supersequence
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1511-count-number-of-teams
1986-largest-color-value-in-a-directed-graph
2061-painting-a-grid-with-three-different-colors
2164-two-best-non-overlapping-events
2262-solving-questions-with-brainpower
2586-longest-square-streak-in-an-array
3106-length-of-the-longest-subsequence-that-sums-to-target
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
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations

Graph

0547-number-of-provinces
0813-all-paths-from-source-to-target
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1916-find-center-of-star-graph
1986-largest-color-value-in-a-directed-graph
2438-find-closest-node-to-given-two-nodes
3189-find-champion-ii
3439-find-minimum-diameter-after-merging-two-trees
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Shortest Path

1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Binary Indexed Tree

1511-count-number-of-teams

Math

0002-add-two-numbers
0009-palindrome-number
0043-multiply-strings
0070-climbing-stairs
0172-factorial-trailing-zeroes
0189-rotate-array
0231-power-of-two
0263-ugly-number
0264-ugly-number-ii
0326-power-of-three
0368-largest-divisible-subset
0371-sum-of-two-integers
0423-reconstruct-original-digits-from-english
0464-can-i-win
0539-minimum-time-difference
0670-maximum-swap
0797-rabbits-in-forest
1013-fibonacci-number
1369-minimum-swaps-to-make-strings-equal
1421-find-numbers-with-even-number-of-digits
1477-product-of-the-last-k-numbers
1889-check-if-number-is-a-sum-of-powers-of-three
1993-sum-of-all-subset-xor-totals
2149-remove-colored-pieces-if-both-neighbors-are-the-same-color
2160-minimum-operations-to-make-a-uni-value-grid
2649-count-total-number-of-colored-cells
2716-prime-subtraction-operation
2998-count-symmetric-integers
3055-maximum-odd-binary-number
3172-divisible-and-non-divisible-sums-difference
3227-find-missing-and-repeated-values
3321-type-of-triangle
3555-final-array-state-after-k-multiplication-operations-i
3629-total-characters-in-string-after-transformations-i
3637-count-number-of-balanced-permutations

Binary Search

0004-median-of-two-sorted-arrays
0167-two-sum-ii-input-array-is-sorted
0300-longest-increasing-subsequence
0718-maximum-length-of-repeated-subarray
0719-find-k-th-smallest-pair-distance
0792-binary-search
0853-most-profit-assigning-work
0892-shortest-subarray-with-sum-at-least-k
1273-compare-strings-by-frequency-of-the-smallest-character
1321-get-equal-substrings-within-budget
1463-the-k-weakest-rows-in-a-matrix
1468-check-if-n-and-its-double-exist
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1886-minimum-limit-of-balls-in-a-bag
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2394-count-subarrays-with-score-less-than-k
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2673-maximize-win-from-two-segments
2716-prime-subtraction-operation

Bit Manipulation

0078-subsets
0090-subsets-ii
0136-single-number
0137-single-number-ii
0191-number-of-1-bits
0231-power-of-two
0260-single-number-iii
0338-counting-bits
0371-sum-of-two-integers
0464-can-i-win
0526-beautiful-arrangement
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
1940-maximum-xor-for-each-query
1993-sum-of-all-subset-xor-totals
2059-unique-length-3-palindromic-subsequences
2323-minimum-bit-flips-to-convert-number
2356-largest-combination-with-bitwise-and-greater-than-zero
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3291-find-if-array-can-be-sorted
3307-find-the-maximum-sum-of-node-values
3380-shortest-subarray-with-or-at-least-k-ii
3394-minimum-array-end

Depth-First Search

0079-word-search
0094-binary-tree-inorder-traversal
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0124-binary-tree-maximum-path-sum
0130-surrounded-regions
0145-binary-tree-postorder-traversal
0200-number-of-islands
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0236-lowest-common-ancestor-of-a-binary-tree
0386-lexicographical-numbers
0515-find-largest-value-in-each-tree-row
0547-number-of-provinces
0617-merge-two-binary-trees
0813-all-paths-from-source-to-target
0832-binary-tree-pruning
1008-binary-tree-cameras
1029-vertical-order-traversal-of-a-binary-tree
1396-count-servers-that-communicate
2438-find-closest-node-to-given-two-nodes
3439-find-minimum-diameter-after-merging-two-trees
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Monotonic Stack

0739-daily-temperatures
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted

Binary Search Tree

0230-kth-smallest-element-in-a-bst
0789-kth-largest-element-in-a-stream

Data Stream

0789-kth-largest-element-in-a-stream
1477-product-of-the-last-k-numbers

Recursion

0002-add-two-numbers
0024-swap-nodes-in-pairs
0044-wildcard-matching
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0326-power-of-three
1013-fibonacci-number

Memoization

0070-climbing-stairs
0464-can-i-win
1013-fibonacci-number
1986-largest-color-value-in-a-directed-graph

Linked List

0002-add-two-numbers
0024-swap-nodes-in-pairs
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list

Trie

0386-lexicographical-numbers
3309-count-prefix-and-suffix-pairs-i

Sliding Window

0003-longest-substring-without-repeating-characters
0567-permutation-in-string
0718-maximum-length-of-repeated-subarray
0892-shortest-subarray-with-sum-at-least-k
1321-get-equal-substrings-within-budget
1460-number-of-substrings-containing-all-three-characters
2394-count-subarrays-with-score-less-than-k
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2527-count-subarrays-with-fixed-bounds
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2673-maximize-win-from-two-segments
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3380-shortest-subarray-with-or-at-least-k-ii
3483-alternating-groups-ii
3522-find-the-power-of-k-size-subarrays-i
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii

Union Find

0130-surrounded-regions
0200-number-of-islands
0547-number-of-provinces
1396-count-servers-that-communicate

String Matching

0812-rotate-string
1524-string-matching-in-an-array
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Game Theory

0464-can-i-win
2149-remove-colored-pieces-if-both-neighbors-are-the-same-color

Backtracking

0022-generate-parentheses
0046-permutations
0047-permutations-ii
0077-combinations
0078-subsets
0079-word-search
0090-subsets-ii
0494-target-sum
0526-beautiful-arrangement
0813-all-paths-from-source-to-target
1993-sum-of-all-subset-xor-totals
2107-find-unique-binary-string

Number Theory

2716-prime-subtraction-operation

Rolling Hash

0718-maximum-length-of-repeated-subarray
3309-count-prefix-and-suffix-pairs-i

Hash Function

0718-maximum-length-of-repeated-subarray
3309-count-prefix-and-suffix-pairs-i

Brainteaser

2533-bitwise-xor-of-all-pairings

Quickselect

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

Queue

0225-implement-stack-using-queues
0387-first-unique-character-in-a-string
0892-shortest-subarray-with-sum-at-least-k
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Monotonic Queue

0892-shortest-subarray-with-sum-at-least-k
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Combinatorics

1993-sum-of-all-subset-xor-totals
3637-count-number-of-balanced-permutations

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2215-finding-3-digit-even-numbers
2998-count-symmetric-integers

Bitmask

0464-can-i-win
0526-beautiful-arrangement

Topological Sort

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