leetcode

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

LeetCode Topics

Math

0048-rotate-image
0050-powx-n
0062-unique-paths
0070-climbing-stairs
0089-gray-code
0149-max-points-on-a-line
0231-power-of-two
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0273-integer-to-english-words
0326-power-of-three
0342-power-of-four
0365-water-and-jug-problem
0368-largest-divisible-subset
0380-insert-delete-getrandom-o1
0523-continuous-subarray-sum
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0650-2-keys-keyboard
0670-maximum-swap
0797-rabbits-in-forest
0870-magic-squares-in-grid
1240-stone-game-ii
1421-find-numbers-with-even-number-of-digits
1500-count-largest-group
1553-count-triplets-that-can-form-two-arrays-of-equal-xor
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
2050-count-good-numbers
2155-find-missing-observations
2160-minimum-operations-to-make-a-uni-value-grid
2415-count-the-number-of-ideal-arrays
2610-closest-prime-numbers-in-range
2649-count-total-number-of-colored-cells
2716-prime-subtraction-operation
2919-maximum-number-of-groups-with-increasing-length
2998-count-symmetric-integers
3001-apply-operations-to-maximize-score
3227-find-missing-and-repeated-values
3243-count-the-number-of-powerful-integers
3548-find-the-count-of-good-integers

String

0003-longest-substring-without-repeating-characters
0010-regular-expression-matching
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0038-count-and-say
0049-group-anagrams
0076-minimum-window-substring
0093-restore-ip-addresses
0127-word-ladder
0132-palindrome-partitioning-ii
0139-word-break
0140-word-break-ii
0179-largest-number
0212-word-search-ii
0214-shortest-palindrome
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0297-serialize-and-deserialize-binary-tree
0438-find-all-anagrams-in-a-string
0472-concatenated-words
0516-longest-palindromic-subsequence
0564-find-the-closest-palindrome
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0609-find-duplicate-file-in-system
0721-accounts-merge
0768-partition-labels
0778-reorganize-string
0868-push-dominoes
0920-uncommon-words-from-two-sentences
0957-minimum-add-to-make-parentheses-valid
0962-flip-string-to-monotone-increasing
1093-recover-a-tree-from-preorder-traversal
1129-longest-string-chain
1170-shortest-common-supersequence
1197-parsing-a-boolean-expression
1304-longest-happy-string
1350-remove-sub-folders-from-the-filesystem
1360-maximum-length-of-a-concatenated-string-with-unique-characters
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
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1715-split-a-string-into-the-max-number-of-unique-substrings
1770-minimum-deletions-to-make-character-frequencies-unique
1786-count-the-number-of-consistent-strings
1894-merge-strings-alternately
2076-sum-of-digits-of-string-after-convert
2095-minimum-number-of-swaps-to-make-the-string-balanced
2107-find-unique-binary-string
2165-plates-between-candles
2220-find-all-possible-recipes-from-given-supplies
2232-adding-spaces-to-a-string
2243-check-if-all-as-appears-before-all-bs
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2580-circular-sentence
2599-take-k-of-each-character-from-left-and-right
2800-minimum-string-length-after-removing-substrings
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3195-separate-black-and-white-balls
3243-count-the-number-of-powerful-integers
3329-find-the-length-of-the-longest-common-prefix
3451-string-compression-iii
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3753-maximum-difference-between-even-and-odd-frequency-i

Recursion

0010-regular-expression-matching
0025-reverse-nodes-in-k-group
0050-powx-n
0231-power-of-two
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
0326-power-of-three
0342-power-of-four
1197-parsing-a-boolean-expression
2050-count-good-numbers

Tree

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0109-convert-sorted-list-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0235-lowest-common-ancestor-of-a-binary-search-tree
0297-serialize-and-deserialize-binary-tree
0337-house-robber-iii
0437-path-sum-iii
0637-average-of-levels-in-binary-tree
0772-construct-quad-tree
0776-n-ary-tree-postorder-traversal
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0896-smallest-subtree-with-all-the-deepest-nodes
0988-flip-equivalent-binary-trees
1029-vertical-order-traversal-of-a-binary-tree
1093-recover-a-tree-from-preorder-traversal
1114-binary-search-tree-to-greater-sum-tree
1116-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1474-longest-zigzag-path-in-a-binary-tree
1484-linked-list-in-binary-tree
1722-throne-inheritance
2545-height-of-binary-tree-after-subtree-removal-queries
2564-most-profitable-path-in-a-tree
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii

Depth-First Search

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0101-symmetric-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0235-lowest-common-ancestor-of-a-binary-search-tree
0297-serialize-and-deserialize-binary-tree
0332-reconstruct-itinerary
0337-house-robber-iii
0365-water-and-jug-problem
0386-lexicographical-numbers
0417-pacific-atlantic-water-flow
0419-battleships-in-a-board
0437-path-sum-iii
0472-concatenated-words
0547-number-of-provinces
0637-average-of-levels-in-binary-tree
0684-redundant-connection
0721-accounts-merge
0733-flood-fill
0744-network-delay-time
0776-n-ary-tree-postorder-traversal
0799-minimum-distance-between-bst-nodes
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0896-smallest-subtree-with-all-the-deepest-nodes
0988-flip-equivalent-binary-trees
1029-vertical-order-traversal-of-a-binary-tree
1093-recover-a-tree-from-preorder-traversal
1114-binary-search-tree-to-greater-sum-tree
1116-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1350-remove-sub-folders-from-the-filesystem
1380-number-of-closed-islands
1387-find-elements-in-a-contaminated-binary-tree
1474-longest-zigzag-path-in-a-binary-tree
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
1722-throne-inheritance
1753-path-with-minimum-effort
2035-count-sub-islands
2101-last-day-where-you-can-still-cross
2545-height-of-binary-tree-after-subtree-removal-queries
2564-most-profitable-path-in-a-tree
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components

Binary Search Tree

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0235-lowest-common-ancestor-of-a-binary-search-tree
0300-longest-increasing-subsequence
0354-russian-doll-envelopes
0378-kth-smallest-element-in-a-sorted-matrix
0410-split-array-largest-sum
0540-single-element-in-a-sorted-array
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0892-shortest-subarray-with-sum-at-least-k
1114-binary-search-tree-to-greater-sum-tree
1335-maximum-candies-allocated-to-k-children
1352-maximum-profit-in-job-scheduling
1646-kth-missing-positive-number
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1753-path-with-minimum-effort
1766-minimum-number-of-removals-to-make-mountain-array
1886-minimum-limit-of-balls-in-a-bag
1929-maximum-value-at-a-given-index-in-a-bounded-array
2000-minimum-speed-to-arrive-on-time
2006-find-the-student-that-will-replace-the-chalk
2101-last-day-where-you-can-still-cross
2165-plates-between-candles
2180-maximum-number-of-tasks-you-can-assign
2188-minimized-maximum-of-products-distributed-to-any-store
2280-count-good-triplets-in-an-array
2294-minimum-time-to-complete-trips
2394-count-subarrays-with-score-less-than-k
2586-longest-square-streak-in-an-array
2614-maximum-count-of-positive-integer-and-negative-integer
2640-maximum-number-of-integers-to-choose-from-a-range-i
2665-minimum-time-to-repair-cars
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2919-maximum-number-of-groups-with-increasing-length
3184-maximum-balanced-subsequence-sum
3427-special-array-ii
3643-zero-array-transformation-ii

Binary Tree

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0109-convert-sorted-list-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0145-binary-tree-postorder-traversal
0235-lowest-common-ancestor-of-a-binary-search-tree
0297-serialize-and-deserialize-binary-tree
0337-house-robber-iii
0437-path-sum-iii
0637-average-of-levels-in-binary-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0896-smallest-subtree-with-all-the-deepest-nodes
0988-flip-equivalent-binary-trees
1029-vertical-order-traversal-of-a-binary-tree
1093-recover-a-tree-from-preorder-traversal
1114-binary-search-tree-to-greater-sum-tree
1116-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1474-longest-zigzag-path-in-a-binary-tree
1484-linked-list-in-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii

Breadth-First Search

0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0127-word-ladder
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0297-serialize-and-deserialize-binary-tree
0322-coin-change
0365-water-and-jug-problem
0417-pacific-atlantic-water-flow
0547-number-of-provinces
0637-average-of-levels-in-binary-tree
0684-redundant-connection
0721-accounts-merge
0733-flood-fill
0744-network-delay-time
0787-sliding-puzzle
0799-minimum-distance-between-bst-nodes
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0833-bus-routes
0896-smallest-subtree-with-all-the-deepest-nodes
1029-vertical-order-traversal-of-a-binary-tree
1116-maximum-level-sum-of-a-binary-tree
1171-shortest-path-in-binary-matrix
1218-lowest-common-ancestor-of-deepest-leaves
1380-number-of-closed-islands
1387-find-elements-in-a-contaminated-binary-tree
1414-shortest-path-in-a-grid-with-obstacles-elimination
1484-linked-list-in-binary-tree
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
2035-count-sub-islands
2101-last-day-where-you-can-still-cross
2545-height-of-binary-tree-after-subtree-removal-queries
2564-most-profitable-path-in-a-tree
2588-maximum-number-of-points-from-grid-queries
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components
3517-shortest-distance-after-road-addition-queries-i

Array

0004-median-of-two-sorted-arrays
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0033-search-in-rotated-sorted-array
0035-search-insert-position
0036-valid-sudoku
0037-sudoku-solver
0040-combination-sum-ii
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0048-rotate-image
0049-group-anagrams
0051-n-queens
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0059-spiral-matrix-ii
0063-unique-paths-ii
0064-minimum-path-sum
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0090-subsets-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0121-best-time-to-buy-and-sell-stock
0134-gas-station
0135-candy
0137-single-number-ii
0139-word-break
0140-word-break-ii
0149-max-points-on-a-line
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0179-largest-number
0198-house-robber
0200-number-of-islands
0212-word-search-ii
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0238-product-of-array-except-self
0239-sliding-window-maximum
0260-single-number-iii
0300-longest-increasing-subsequence
0304-range-sum-query-2d-immutable
0322-coin-change
0347-top-k-frequent-elements
0354-russian-doll-envelopes
0368-largest-divisible-subset
0377-combination-sum-iv
0378-kth-smallest-element-in-a-sorted-matrix
0380-insert-delete-getrandom-o1
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0419-battleships-in-a-board
0472-concatenated-words
0491-non-decreasing-subsequences
0523-continuous-subarray-sum
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0609-find-duplicate-file-in-system
0632-smallest-range-covering-elements-from-k-lists
0646-maximum-length-of-pair-chain
0719-find-k-th-smallest-pair-distance
0721-accounts-merge
0729-my-calendar-i
0731-my-calendar-ii
0733-flood-fill
0735-asteroid-collision
0772-construct-quad-tree
0787-sliding-puzzle
0797-rabbits-in-forest
0833-bus-routes
0859-design-circular-deque
0870-magic-squares-in-grid
0883-car-fleet
0887-minimum-cost-to-hire-k-workers
0890-lemonade-change
0892-shortest-subarray-with-sum-at-least-k
0906-walking-robot-simulation
0921-spiral-matrix-iii
0943-sum-of-subarray-minimums
0967-minimum-falling-path-sum
1002-maximum-width-ramp
1022-unique-paths-iii
1025-minimum-cost-for-tickets
1028-interval-list-intersections
1049-minimum-domino-rotations-for-equal-row
1129-longest-string-chain
1147-flip-columns-for-maximum-number-of-equal-rows
1171-shortest-path-in-binary-matrix
1217-relative-sort-array
1227-number-of-equivalent-domino-pairs
1240-stone-game-ii
1256-rank-transform-of-an-array
1293-three-consecutive-odds
1305-number-of-visible-people-in-a-queue
1325-path-with-maximum-probability
1331-path-with-maximum-gold
1335-maximum-candies-allocated-to-k-children
1350-remove-sub-folders-from-the-filesystem
1352-maximum-profit-in-job-scheduling
1360-maximum-length-of-a-concatenated-string-with-unique-characters
1380-number-of-closed-islands
1402-count-square-submatrices-with-all-ones
1414-shortest-path-in-a-grid-with-obstacles-elimination
1418-fair-distribution-of-cookies
1421-find-numbers-with-even-number-of-digits
1435-xor-queries-of-a-subarray
1457-minimum-difficulty-of-a-job-schedule
1458-sort-integers-by-the-number-of-1-bits
1478-maximum-number-of-events-that-can-be-attended
1497-design-a-stack-with-increment-operation
1499-maximum-performance-of-a-team
1553-count-triplets-that-can-form-two-arrays-of-equal-xor
1620-check-if-array-pairs-are-divisible-by-k
1631-number-of-sub-arrays-with-odd-sum
1646-kth-missing-positive-number
1656-count-good-triplets
1669-minimum-cost-to-cut-a-stick
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1691-minimum-number-of-days-to-disconnect-island
1694-make-sum-divisible-by-p
1706-min-cost-to-connect-all-points
1723-maximum-number-of-achievable-transfer-requests
1753-path-with-minimum-effort
1755-defuse-the-bomb
1766-minimum-number-of-removals-to-make-mountain-array
1786-count-the-number-of-consistent-strings
1849-maximum-absolute-sum-of-any-subarray
1878-check-if-array-is-sorted-and-rotated
1886-minimum-limit-of-balls-in-a-bag
1917-maximum-average-pass-ratio
1940-maximum-xor-for-each-query
1972-rotating-the-box
1993-sum-of-all-subset-xor-totals
2000-minimum-speed-to-arrive-on-time
2006-find-the-student-that-will-replace-the-chalk
2022-maximum-alternating-subsequence-sum
2035-count-sub-islands
2048-build-array-from-permutation
2054-the-number-of-the-smallest-unoccupied-chair
2058-concatenation-of-array
2067-maximum-number-of-points-with-cost
2101-last-day-where-you-can-still-cross
2107-find-unique-binary-string
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2160-minimum-operations-to-make-a-uni-value-grid
2165-plates-between-candles
2170-count-number-of-maximum-bitwise-or-subsets
2180-maximum-number-of-tasks-you-can-assign
2188-minimized-maximum-of-products-distributed-to-any-store
2220-find-all-possible-recipes-from-given-supplies
2232-adding-spaces-to-a-string
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
2280-count-good-triplets-in-an-array
2294-minimum-time-to-complete-trips
2308-divide-array-into-equal-pairs
2343-count-unguarded-cells-in-the-grid
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2478-longest-nice-subarray
2488-divide-intervals-into-minimum-number-of-groups
2503-longest-subarray-with-maximum-bitwise-and
2519-find-the-original-array-of-prefix-xor
2527-count-subarrays-with-fixed-bounds
2545-height-of-binary-tree-after-subtree-removal-queries
2551-apply-operations-to-an-array
2552-maximum-sum-of-distinct-subarrays-with-length-k
2554-minimum-total-distance-traveled
2564-most-profitable-path-in-a-tree
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2588-maximum-number-of-points-from-grid-queries
2614-maximum-count-of-positive-integer-and-negative-integer
2616-maximal-score-after-applying-k-operations
2626-count-the-number-of-good-subarrays
2640-maximum-number-of-integers-to-choose-from-a-range-i
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2690-house-robber-iv
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
2716-prime-subtraction-operation
2764-maximum-number-of-fish-in-a-grid
2794-maximum-number-of-moves-in-a-grid
2856-count-complete-subarrays-in-an-array
2868-continuous-subarrays
2888-minimum-index-of-a-valid-split
2919-maximum-number-of-groups-with-increasing-length
3001-apply-operations-to-maximize-score
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3184-maximum-balanced-subsequence-sum
3213-count-subarrays-where-max-element-appears-at-least-k-times
3227-find-missing-and-repeated-values
3291-find-if-array-can-be-sorted
3329-find-the-length-of-the-longest-common-prefix
3348-minimum-cost-walk-in-weighted-graph
3383-taking-maximum-energy-from-the-mystic-dungeon
3427-special-array-ii
3429-special-array-i
3430-count-days-without-meetings
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3517-shortest-distance-after-road-addition-queries-i
3522-find-the-power-of-k-size-subarrays-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
3643-zero-array-transformation-ii
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3657-check-if-grid-can-be-cut-into-sections
3685-count-subarrays-of-length-three-with-a-condition
3759-choose-k-elements-with-maximum-sum

Matrix

0036-valid-sudoku
0037-sudoku-solver
0048-rotate-image
0054-spiral-matrix
0059-spiral-matrix-ii
0063-unique-paths-ii
0064-minimum-path-sum
0074-search-a-2d-matrix
0200-number-of-islands
0212-word-search-ii
0304-range-sum-query-2d-immutable
0378-kth-smallest-element-in-a-sorted-matrix
0417-pacific-atlantic-water-flow
0419-battleships-in-a-board
0733-flood-fill
0772-construct-quad-tree
0787-sliding-puzzle
0870-magic-squares-in-grid
0921-spiral-matrix-iii
0967-minimum-falling-path-sum
1022-unique-paths-iii
1147-flip-columns-for-maximum-number-of-equal-rows
1171-shortest-path-in-binary-matrix
1331-path-with-maximum-gold
1380-number-of-closed-islands
1402-count-square-submatrices-with-all-ones
1414-shortest-path-in-a-grid-with-obstacles-elimination
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
1972-rotating-the-box
2035-count-sub-islands
2101-last-day-where-you-can-still-cross
2132-convert-1d-array-into-2d-array
2160-minimum-operations-to-make-a-uni-value-grid
2343-count-unguarded-cells-in-the-grid
2588-maximum-number-of-points-from-grid-queries
2764-maximum-number-of-fish-in-a-grid
2794-maximum-number-of-moves-in-a-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

Simulation

0054-spiral-matrix
0059-spiral-matrix-ii
0592-fraction-addition-and-subtraction
0735-asteroid-collision
0906-walking-robot-simulation
0921-spiral-matrix-iii
2006-find-the-student-that-will-replace-the-chalk
2048-build-array-from-permutation
2058-concatenation-of-array
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2232-adding-spaces-to-a-string
2265-partition-array-according-to-given-pivot
2343-count-unguarded-cells-in-the-grid
2551-apply-operations-to-an-array
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2800-minimum-string-length-after-removing-substrings

Hash Table

0003-longest-substring-without-repeating-characters
0036-valid-sudoku
0037-sudoku-solver
0049-group-anagrams
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0127-word-ladder
0138-copy-list-with-random-pointer
0139-word-break
0140-word-break-ii
0146-lru-cache
0149-max-points-on-a-line
0264-ugly-number-ii
0347-top-k-frequent-elements
0380-insert-delete-getrandom-o1
0432-all-oone-data-structure
0438-find-all-anagrams-in-a-string
0460-lfu-cache
0491-non-decreasing-subsequences
0523-continuous-subarray-sum
0560-subarray-sum-equals-k
0567-permutation-in-string
0609-find-duplicate-file-in-system
0632-smallest-range-covering-elements-from-k-lists
0721-accounts-merge
0768-partition-labels
0778-reorganize-string
0797-rabbits-in-forest
0833-bus-routes
0870-magic-squares-in-grid
0896-smallest-subtree-with-all-the-deepest-nodes
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
1029-vertical-order-traversal-of-a-binary-tree
1129-longest-string-chain
1147-flip-columns-for-maximum-number-of-equal-rows
1217-relative-sort-array
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1256-rank-transform-of-an-array
1267-remove-zero-sum-consecutive-nodes-from-linked-list
1387-find-elements-in-a-contaminated-binary-tree
1460-number-of-substrings-containing-all-three-characters
1473-find-the-longest-substring-containing-vowels-in-even-counts
1500-count-largest-group
1553-count-triplets-that-can-form-two-arrays-of-equal-xor
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1715-split-a-string-into-the-max-number-of-unique-substrings
1722-throne-inheritance
1770-minimum-deletions-to-make-character-frequencies-unique
1786-count-the-number-of-consistent-strings
2054-the-number-of-the-smallest-unoccupied-chair
2107-find-unique-binary-string
2220-find-all-possible-recipes-from-given-supplies
2308-divide-array-into-equal-pairs
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
2626-count-the-number-of-good-subarrays
2640-maximum-number-of-integers-to-choose-from-a-range-i
2677-cousins-in-binary-tree-ii
2695-find-score-of-an-array-after-marking-all-elements
2707-merge-two-2d-arrays-by-summing-values
2856-count-complete-subarrays-in-an-array
2888-minimum-index-of-a-valid-split
3227-find-missing-and-repeated-values
3329-find-the-length-of-the-longest-common-prefix
3548-find-the-count-of-good-integers
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3753-maximum-difference-between-even-and-odd-frequency-i

Design

0146-lru-cache
0295-find-median-from-data-stream
0297-serialize-and-deserialize-binary-tree
0304-range-sum-query-2d-immutable
0380-insert-delete-getrandom-o1
0432-all-oone-data-structure
0460-lfu-cache
0729-my-calendar-i
0731-my-calendar-ii
0789-kth-largest-element-in-a-stream
0859-design-circular-deque
1387-find-elements-in-a-contaminated-binary-tree
1497-design-a-stack-with-increment-operation
1722-throne-inheritance

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0264-ugly-number-ii
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0378-kth-smallest-element-in-a-sorted-matrix
0632-smallest-range-covering-elements-from-k-lists
0744-network-delay-time
0778-reorganize-string
0789-kth-largest-element-in-a-stream
0803-cheapest-flights-within-k-stops
0887-minimum-cost-to-hire-k-workers
0892-shortest-subarray-with-sum-at-least-k
1304-longest-happy-string
1325-path-with-maximum-probability
1478-maximum-number-of-events-that-can-be-attended
1499-maximum-performance-of-a-team
1753-path-with-minimum-effort
1917-maximum-average-pass-ratio
2054-the-number-of-the-smallest-unoccupied-chair
2488-divide-intervals-into-minimum-number-of-groups
2588-maximum-number-of-points-from-grid-queries
2616-maximal-score-after-applying-k-operations
2681-put-marbles-in-bags
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2803-modify-graph-edge-weights
2868-continuous-subarrays
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3759-choose-k-elements-with-maximum-sum

Data Stream

0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream

Backtracking

0022-generate-parentheses
0037-sudoku-solver
0040-combination-sum-ii
0046-permutations
0047-permutations-ii
0051-n-queens
0077-combinations
0089-gray-code
0090-subsets-ii
0093-restore-ip-addresses
0140-word-break-ii
0212-word-search-ii
0491-non-decreasing-subsequences
1022-unique-paths-iii
1331-path-with-maximum-gold
1360-maximum-length-of-a-concatenated-string-with-unique-characters
1418-fair-distribution-of-cookies
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1715-split-a-string-into-the-max-number-of-unique-substrings
1723-maximum-number-of-achievable-transfer-requests
1993-sum-of-all-subset-xor-totals
2107-find-unique-binary-string
2170-count-number-of-maximum-bitwise-or-subsets

Two Pointers

0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0042-trapping-rain-water
0088-merge-sorted-array
0167-two-sum-ii-input-array-is-sorted
0295-find-median-from-data-stream
0567-permutation-in-string
0719-find-k-th-smallest-pair-distance
0768-partition-labels
0868-push-dominoes
1028-interval-list-intersections
1129-longest-string-chain
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1894-merge-strings-alternately
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2232-adding-spaces-to-a-string
2265-partition-array-according-to-given-pivot
2488-divide-intervals-into-minimum-number-of-groups
2551-apply-operations-to-an-array
2581-divide-players-into-teams-of-equal-skill
2588-maximum-number-of-points-from-grid-queries
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3195-separate-black-and-white-balls

Sorting

0015-3sum
0047-permutations-ii
0049-group-anagrams
0056-merge-intervals
0088-merge-sorted-array
0179-largest-number
0215-kth-largest-element-in-an-array
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0354-russian-doll-envelopes
0368-largest-divisible-subset
0378-kth-smallest-element-in-a-sorted-matrix
0632-smallest-range-covering-elements-from-k-lists
0646-maximum-length-of-pair-chain
0719-find-k-th-smallest-pair-distance
0721-accounts-merge
0778-reorganize-string
0883-car-fleet
0887-minimum-cost-to-hire-k-workers
1029-vertical-order-traversal-of-a-binary-tree
1129-longest-string-chain
1217-relative-sort-array
1256-rank-transform-of-an-array
1352-maximum-profit-in-job-scheduling
1458-sort-integers-by-the-number-of-1-bits
1478-maximum-number-of-events-that-can-be-attended
1499-maximum-performance-of-a-team
1669-minimum-cost-to-cut-a-stick
1770-minimum-deletions-to-make-character-frequencies-unique
2160-minimum-operations-to-make-a-uni-value-grid
2180-maximum-number-of-tasks-you-can-assign
2488-divide-intervals-into-minimum-number-of-groups
2554-minimum-total-distance-traveled
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2588-maximum-number-of-points-from-grid-queries
2640-maximum-number-of-integers-to-choose-from-a-range-i
2646-kth-largest-sum-in-a-binary-tree
2681-put-marbles-in-bags
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2888-minimum-index-of-a-valid-split
2919-maximum-number-of-groups-with-increasing-length
3001-apply-operations-to-maximize-score
3291-find-if-array-can-be-sorted
3430-count-days-without-meetings
3657-check-if-grid-can-be-cut-into-sections
3759-choose-k-elements-with-maximum-sum

Greedy

0045-jump-game-ii
0055-jump-game
0134-gas-station
0135-candy
0179-largest-number
0410-split-array-largest-sum
0632-smallest-range-covering-elements-from-k-lists
0646-maximum-length-of-pair-chain
0670-maximum-swap
0768-partition-labels
0778-reorganize-string
0797-rabbits-in-forest
0887-minimum-cost-to-hire-k-workers
0890-lemonade-change
0957-minimum-add-to-make-parentheses-valid
1049-minimum-domino-rotations-for-equal-row
1304-longest-happy-string
1478-maximum-number-of-events-that-can-be-attended
1499-maximum-performance-of-a-team
1766-minimum-number-of-removals-to-make-mountain-array
1770-minimum-deletions-to-make-character-frequencies-unique
1917-maximum-average-pass-ratio
1929-maximum-value-at-a-given-index-in-a-bounded-array
2095-minimum-number-of-swaps-to-make-the-string-balanced
2180-maximum-number-of-tasks-you-can-assign
2488-divide-intervals-into-minimum-number-of-groups
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
2681-put-marbles-in-bags
2716-prime-subtraction-operation
2919-maximum-number-of-groups-with-increasing-length
3001-apply-operations-to-maximize-score
3195-separate-black-and-white-balls

Dynamic Programming

0010-regular-expression-matching
0022-generate-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0121-best-time-to-buy-and-sell-stock
0124-binary-tree-maximum-path-sum
0132-palindrome-partitioning-ii
0139-word-break
0140-word-break-ii
0198-house-robber
0213-house-robber-ii
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0300-longest-increasing-subsequence
0322-coin-change
0337-house-robber-iii
0354-russian-doll-envelopes
0368-largest-divisible-subset
0377-combination-sum-iv
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0472-concatenated-words
0516-longest-palindromic-subsequence
0646-maximum-length-of-pair-chain
0650-2-keys-keyboard
0803-cheapest-flights-within-k-stops
0806-domino-and-tromino-tiling
0868-push-dominoes
0943-sum-of-subarray-minimums
0962-flip-string-to-monotone-increasing
0967-minimum-falling-path-sum
1025-minimum-cost-for-tickets
1129-longest-string-chain
1170-shortest-common-supersequence
1240-stone-game-ii
1352-maximum-profit-in-job-scheduling
1402-count-square-submatrices-with-all-ones
1418-fair-distribution-of-cookies
1437-minimum-insertion-steps-to-make-a-string-palindrome
1457-minimum-difficulty-of-a-job-schedule
1474-longest-zigzag-path-in-a-binary-tree
1631-number-of-sub-arrays-with-odd-sum
1669-minimum-cost-to-cut-a-stick
1766-minimum-number-of-removals-to-make-mountain-array
1849-maximum-absolute-sum-of-any-subarray
2022-maximum-alternating-subsequence-sum
2067-maximum-number-of-points-with-cost
2090-number-of-ways-to-arrive-at-destination
2262-solving-questions-with-brainpower
2415-count-the-number-of-ideal-arrays
2554-minimum-total-distance-traveled
2562-count-ways-to-build-good-strings
2586-longest-square-streak-in-an-array
2794-maximum-number-of-moves-in-a-grid
3184-maximum-balanced-subsequence-sum
3243-count-the-number-of-powerful-integers

Prefix Sum

0238-product-of-array-except-self
0304-range-sum-query-2d-immutable
0410-split-array-largest-sum
0523-continuous-subarray-sum
0560-subarray-sum-equals-k
0731-my-calendar-ii
0892-shortest-subarray-with-sum-at-least-k
1240-stone-game-ii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1553-count-triplets-that-can-form-two-arrays-of-equal-xor
1631-number-of-sub-arrays-with-odd-sum
1694-make-sum-divisible-by-p
1940-maximum-xor-for-each-query
2006-find-the-student-that-will-replace-the-chalk
2165-plates-between-candles
2249-count-the-hidden-sequences
2394-count-subarrays-with-score-less-than-k
2465-shifting-letters-ii
2488-divide-intervals-into-minimum-number-of-groups
3383-taking-maximum-energy-from-the-mystic-dungeon
3427-special-array-ii
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3643-zero-array-transformation-ii

Game Theory

1240-stone-game-ii

Bit Manipulation

0089-gray-code
0090-subsets-ii
0137-single-number-ii
0231-power-of-two
0260-single-number-iii
0342-power-of-four
0476-number-complement
0491-non-decreasing-subsequences
1022-unique-paths-iii
1360-maximum-length-of-a-concatenated-string-with-unique-characters
1418-fair-distribution-of-cookies
1435-xor-queries-of-a-subarray
1458-sort-integers-by-the-number-of-1-bits
1473-find-the-longest-substring-containing-vowels-in-even-counts
1553-count-triplets-that-can-form-two-arrays-of-equal-xor
1723-maximum-number-of-achievable-transfer-requests
1786-count-the-number-of-consistent-strings
1940-maximum-xor-for-each-query
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2308-divide-array-into-equal-pairs
2323-minimum-bit-flips-to-convert-number
2478-longest-nice-subarray
2503-longest-subarray-with-maximum-bitwise-and
2519-find-the-original-array-of-prefix-xor
3291-find-if-array-can-be-sorted
3348-minimum-cost-walk-in-weighted-graph
3394-minimum-array-end
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Stack

0020-valid-parentheses
0042-trapping-rain-water
0114-flatten-binary-tree-to-linked-list
0145-binary-tree-postorder-traversal
0735-asteroid-collision
0776-n-ary-tree-postorder-traversal
0883-car-fleet
0943-sum-of-subarray-minimums
0957-minimum-add-to-make-parentheses-valid
1002-maximum-width-ramp
1197-parsing-a-boolean-expression
1305-number-of-visible-people-in-a-queue
1497-design-a-stack-with-increment-operation
1679-shortest-subarray-to-be-removed-to-make-array-sorted
2095-minimum-number-of-swaps-to-make-the-string-balanced
2800-minimum-string-length-after-removing-substrings
3001-apply-operations-to-maximize-score

Graph

0207-course-schedule
0210-course-schedule-ii
0332-reconstruct-itinerary
0547-number-of-provinces
0684-redundant-connection
0744-network-delay-time
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
1325-path-with-maximum-probability
1706-min-cost-to-connect-all-points
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
2564-most-profitable-path-in-a-tree
2793-count-the-number-of-complete-components
2803-modify-graph-edge-weights
3348-minimum-cost-walk-in-weighted-graph
3517-shortest-distance-after-road-addition-queries-i
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Shortest Path

0744-network-delay-time
0803-cheapest-flights-within-k-stops
1325-path-with-maximum-probability
2090-number-of-ways-to-arrive-at-destination
2803-modify-graph-edge-weights
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Union Find

0200-number-of-islands
0547-number-of-provinces
0684-redundant-connection
0721-accounts-merge
0801-is-graph-bipartite
1380-number-of-closed-islands
1706-min-cost-to-connect-all-points
1753-path-with-minimum-effort
2035-count-sub-islands
2101-last-day-where-you-can-still-cross
2588-maximum-number-of-points-from-grid-queries
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph

Strongly Connected Component

1691-minimum-number-of-days-to-disconnect-island

Counting Sort

0347-top-k-frequent-elements
0778-reorganize-string
0920-uncommon-words-from-two-sentences
1217-relative-sort-array
1227-number-of-equivalent-domino-pairs
1458-sort-integers-by-the-number-of-1-bits
1620-check-if-array-pairs-are-divisible-by-k
1786-count-the-number-of-consistent-strings
2308-divide-array-into-equal-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
3753-maximum-difference-between-even-and-odd-frequency-i

Linked List

0023-merge-k-sorted-lists
0025-reverse-nodes-in-k-group
0092-reverse-linked-list-ii
0109-convert-sorted-list-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0138-copy-list-with-random-pointer
0146-lru-cache
0432-all-oone-data-structure
0460-lfu-cache
0725-split-linked-list-in-parts
0859-design-circular-deque
1267-remove-zero-sum-consecutive-nodes-from-linked-list
1484-linked-list-in-binary-tree

Brainteaser

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

Memoization

0070-climbing-stairs
0139-word-break
0140-word-break-ii
0241-different-ways-to-add-parentheses

Rolling Hash

0214-shortest-palindrome

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0214-shortest-palindrome

Hash Function

0214-shortest-palindrome

Trie

0139-word-break
0140-word-break-ii
0212-word-search-ii
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
0472-concatenated-words
1350-remove-sub-folders-from-the-filesystem
3329-find-the-length-of-the-longest-common-prefix

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0109-convert-sorted-list-to-binary-search-tree
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0772-construct-quad-tree
2280-count-good-triplets-in-an-array

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Segment Tree

0729-my-calendar-i
0731-my-calendar-ii
2280-count-good-triplets-in-an-array
3184-maximum-balanced-subsequence-sum

Ordered Set

0729-my-calendar-i
0731-my-calendar-ii
2280-count-good-triplets-in-an-array
2868-continuous-subarrays

Queue

0239-sliding-window-maximum
0859-design-circular-deque
0892-shortest-subarray-with-sum-at-least-k
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds
2868-continuous-subarrays
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i

Doubly-Linked List

0146-lru-cache
0432-all-oone-data-structure
0460-lfu-cache

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0239-sliding-window-maximum
0438-find-all-anagrams-in-a-string
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0892-shortest-subarray-with-sum-at-least-k
1460-number-of-substrings-containing-all-three-characters
1755-defuse-the-bomb
2394-count-subarrays-with-score-less-than-k
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2478-longest-nice-subarray
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
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
2868-continuous-subarrays
3213-count-subarrays-where-max-element-appears-at-least-k-times
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3522-find-the-power-of-k-size-subarrays-i
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii

Monotonic Stack

0042-trapping-rain-water
0883-car-fleet
0943-sum-of-subarray-minimums
1002-maximum-width-ramp
1305-number-of-visible-people-in-a-queue
1679-shortest-subarray-to-be-removed-to-make-array-sorted
3001-apply-operations-to-maximize-score

Topological Sort

0207-course-schedule
0210-course-schedule-ii
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies

Combinatorics

0062-unique-paths
1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays
3548-find-the-count-of-good-integers

Enumeration

1656-count-good-triplets
1723-maximum-number-of-achievable-transfer-requests
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2998-count-symmetric-integers
3548-find-the-count-of-good-integers

Minimum Spanning Tree

1706-min-cost-to-connect-all-points

Binary Indexed Tree

2280-count-good-triplets-in-an-array
3184-maximum-balanced-subsequence-sum

Number Theory

2415-count-the-number-of-ideal-arrays
2610-closest-prime-numbers-in-range
2716-prime-subtraction-operation
3001-apply-operations-to-maximize-score

Bitmask

1418-fair-distribution-of-cookies

Monotonic Queue

0239-sliding-window-maximum
0892-shortest-subarray-with-sum-at-least-k
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds
2868-continuous-subarrays

Merge Sort

0023-merge-k-sorted-lists
2280-count-good-triplets-in-an-array

Randomized

0380-insert-delete-getrandom-o1

Database

1908-recyclable-and-low-fat-products

Eulerian Circuit

0332-reconstruct-itinerary

Geometry

0149-max-points-on-a-line

Line Sweep

1028-interval-list-intersections