DSA

Data Structures & Algorithms

LeetCode Topics

Array

0004-median-of-two-sorted-arrays
0018-4sum
0031-next-permutation
0035-search-insert-position
0037-sudoku-solver
0046-permutations
0054-spiral-matrix
0059-spiral-matrix-ii
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0078-subsets
0079-word-search
0081-search-in-rotated-sorted-array-ii
0085-maximal-rectangle
0088-merge-sorted-array
0090-subsets-ii
0108-convert-sorted-array-to-binary-search-tree
0119-pascals-triangle-ii
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0179-largest-number
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0204-count-primes
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0221-maximal-square
0240-search-a-2d-matrix-ii
0289-game-of-life
0300-longest-increasing-subsequence
0303-range-sum-query-immutable
0322-coin-change
0403-frog-jump
0410-split-array-largest-sum
0421-maximum-xor-of-two-numbers-in-an-array
0493-reverse-pairs
0502-ipo
0506-relative-ranks
0517-super-washing-machines
0524-longest-word-in-dictionary-through-deleting
0566-reshape-the-matrix
0611-valid-triangle-number
0654-maximum-binary-tree
0674-longest-continuous-increasing-subsequence
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0720-longest-word-in-dictionary
0721-accounts-merge
0724-find-pivot-index
0747-min-cost-climbing-stairs
0787-sliding-puzzle
0794-swim-in-rising-water
0837-most-common-word
0854-making-a-large-island
0907-koko-eating-bananas
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0948-sort-an-array
0952-word-subsets
0987-reveal-cards-in-increasing-order
1025-minimum-cost-for-tickets
1056-capacity-to-ship-packages-within-d-days
1080-camelcase-matching
1121-partition-array-for-maximum-sum
1127-last-stone-weight
1171-shortest-path-in-binary-matrix
1207-delete-nodes-and-return-forest
1364-tuple-with-same-product
1379-reconstruct-a-2-row-binary-matrix
1396-count-servers-that-communicate
1397-search-suggestions-system
1402-count-square-submatrices-with-all-ones
1408-find-the-smallest-divisor-given-a-threshold
1421-find-numbers-with-even-number-of-digits
1424-maximum-candies-you-can-get-from-boxes
1468-check-if-n-and-its-double-exist
1477-product-of-the-last-k-numbers
1524-string-matching-in-an-array
1570-final-prices-with-a-special-discount-in-a-shop
1582-design-browser-history
1586-longest-subarray-of-1s-after-deleting-one-element
1605-minimum-number-of-days-to-make-m-bouquets
1631-number-of-sub-arrays-with-odd-sum
1646-kth-missing-positive-number
1669-minimum-cost-to-cut-a-stick
1753-path-with-minimum-effort
1755-defuse-the-bomb
1819-construct-the-lexicographically-largest-valid-sequence
1826-maximum-xor-with-an-element-from-array
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1966-frequency-of-the-most-frequent-element
1972-rotating-the-box
2047-find-a-peak-element-ii
2048-build-array-from-permutation
2093-check-if-string-is-a-prefix-of-array
2094-remove-stones-to-minimize-the-total
2104-operations-on-tree
2106-find-greatest-common-divisor-of-array
2107-find-unique-binary-string
2144-maximum-difference-between-increasing-elements
2215-finding-3-digit-even-numbers
2232-adding-spaces-to-a-string
2265-partition-array-according-to-given-pivot
2270-find-all-lonely-numbers-in-the-array
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2310-minimum-operations-to-halve-array-sum
2341-count-prefixes-of-a-given-string
2343-count-unguarded-cells-in-the-grid
2358-number-of-ways-to-split-array
2375-minimum-obstacle-removal-to-reach-corner
2387-partition-array-such-that-maximum-difference-is-k
2411-spiral-matrix-iv
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2521-paths-in-matrix-whose-sum-is-divisible-by-k
2533-bitwise-xor-of-all-pairings
2543-most-popular-video-creator
2551-apply-operations-to-an-array
2591-frog-jump-ii
2606-difference-between-ones-and-zeros-in-row-and-column
2614-maximum-count-of-positive-integer-and-negative-integer
2640-maximum-number-of-integers-to-choose-from-a-range-i
2685-first-completely-painted-row-or-column
2691-count-vowel-strings-in-ranges
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2711-minimum-time-to-visit-a-cell-in-a-grid
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
2831-number-of-beautiful-pairs
3188-find-champion-i
3194-find-words-containing-character
3219-make-lexicographically-smallest-array-by-swapping-elements
3221-find-the-peaks
3241-divide-array-into-arrays-with-max-difference
3242-count-elements-with-maximum-frequency
3246-check-if-bitwise-or-has-trailing-zeros
3305-count-prefix-and-suffix-pairs-ii
3309-count-prefix-and-suffix-pairs-i
3332-minimum-operations-to-exceed-threshold-value-ii
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3434-find-the-number-of-distinct-colors-among-the-balls
3555-final-array-state-after-k-multiplication-operations-i
3627-find-minimum-time-to-reach-last-room-i
3685-count-subarrays-of-length-three-with-a-condition
3790-fruits-into-baskets-ii

Linked List

0002-add-two-numbers
0025-reverse-nodes-in-k-group
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0206-reverse-linked-list
0237-delete-node-in-a-linked-list
0328-odd-even-linked-list
0355-design-twitter
0908-middle-of-the-linked-list
1582-design-browser-history
2216-delete-the-middle-node-of-a-linked-list
2236-maximum-twin-sum-of-a-linked-list
2411-spiral-matrix-iv

Stack

0085-maximal-rectangle
0155-min-stack
0654-maximum-binary-tree
0931-maximum-frequency-stack
0957-minimum-add-to-make-parentheses-valid
1570-final-prices-with-a-special-discount-in-a-shop
1582-design-browser-history
2221-check-if-a-parentheses-string-can-be-valid
2236-maximum-twin-sum-of-a-linked-list
2456-construct-smallest-number-from-di-string
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits

Design

0155-min-stack
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0295-find-median-from-data-stream
0297-serialize-and-deserialize-binary-tree
0303-range-sum-query-immutable
0355-design-twitter
0789-kth-largest-element-in-a-stream
0931-maximum-frequency-stack
0969-number-of-recent-calls
1023-time-based-key-value-store
1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
1582-design-browser-history
1955-seat-reservation-manager
2104-operations-on-tree
2429-design-a-food-rating-system
2434-design-a-number-container-system

Doubly-Linked List

1582-design-browser-history

Data Stream

0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream
0969-number-of-recent-calls
1477-product-of-the-last-k-numbers
1582-design-browser-history

Tree

0098-validate-binary-search-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0108-convert-sorted-array-to-binary-search-tree
0111-minimum-depth-of-binary-tree
0113-path-sum-ii
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0515-find-largest-value-in-each-tree-row
0637-average-of-levels-in-binary-tree
0654-maximum-binary-tree
0662-maximum-width-of-binary-tree
0764-n-ary-tree-level-order-traversal
0789-kth-largest-element-in-a-stream
0893-all-nodes-distance-k-in-binary-tree
0904-leaf-similar-trees
0925-construct-binary-tree-from-preorder-and-postorder-traversal
1093-recover-a-tree-from-preorder-traversal
1207-delete-nodes-and-return-forest
1254-deepest-leaves-sum
1387-find-elements-in-a-contaminated-binary-tree
1544-count-good-nodes-in-binary-tree
1731-even-odd-tree
2104-operations-on-tree
2384-root-equals-sum-of-children
2461-amount-of-time-for-binary-tree-to-be-infected

Depth-First Search

0079-word-search
0098-validate-binary-search-tree
0101-symmetric-tree
0111-minimum-depth-of-binary-tree
0113-path-sum-ii
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0211-design-add-and-search-words-data-structure
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0515-find-largest-value-in-each-tree-row
0637-average-of-levels-in-binary-tree
0662-maximum-width-of-binary-tree
0721-accounts-merge
0744-network-delay-time
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0854-making-a-large-island
0893-all-nodes-distance-k-in-binary-tree
0904-leaf-similar-trees
1093-recover-a-tree-from-preorder-traversal
1207-delete-nodes-and-return-forest
1254-deepest-leaves-sum
1300-critical-connections-in-a-network
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1442-number-of-operations-to-make-network-connected
1544-count-good-nodes-in-binary-tree
1753-path-with-minimum-effort
2104-operations-on-tree
2461-amount-of-time-for-binary-tree-to-be-infected

Breadth-First Search

0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0111-minimum-depth-of-binary-tree
0127-word-ladder
0199-binary-tree-right-side-view
0297-serialize-and-deserialize-binary-tree
0322-coin-change
0515-find-largest-value-in-each-tree-row
0637-average-of-levels-in-binary-tree
0662-maximum-width-of-binary-tree
0721-accounts-merge
0744-network-delay-time
0764-n-ary-tree-level-order-traversal
0787-sliding-puzzle
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0854-making-a-large-island
0893-all-nodes-distance-k-in-binary-tree
1171-shortest-path-in-binary-matrix
1254-deepest-leaves-sum
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1424-maximum-candies-you-can-get-from-boxes
1442-number-of-operations-to-make-network-connected
1544-count-good-nodes-in-binary-tree
1731-even-odd-tree
1753-path-with-minimum-effort
2104-operations-on-tree
2375-minimum-obstacle-removal-to-reach-corner
2461-amount-of-time-for-binary-tree-to-be-infected
2711-minimum-time-to-visit-a-cell-in-a-grid

Binary Tree

0098-validate-binary-search-tree
0101-symmetric-tree
0103-binary-tree-zigzag-level-order-traversal
0108-convert-sorted-array-to-binary-search-tree
0111-minimum-depth-of-binary-tree
0113-path-sum-ii
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0515-find-largest-value-in-each-tree-row
0637-average-of-levels-in-binary-tree
0654-maximum-binary-tree
0662-maximum-width-of-binary-tree
0789-kth-largest-element-in-a-stream
0893-all-nodes-distance-k-in-binary-tree
0904-leaf-similar-trees
0925-construct-binary-tree-from-preorder-and-postorder-traversal
1093-recover-a-tree-from-preorder-traversal
1207-delete-nodes-and-return-forest
1254-deepest-leaves-sum
1387-find-elements-in-a-contaminated-binary-tree
1544-count-good-nodes-in-binary-tree
1731-even-odd-tree
2384-root-equals-sum-of-children
2461-amount-of-time-for-binary-tree-to-be-infected

Matrix

0037-sudoku-solver
0054-spiral-matrix
0059-spiral-matrix-ii
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0085-maximal-rectangle
0221-maximal-square
0240-search-a-2d-matrix-ii
0289-game-of-life
0566-reshape-the-matrix
0787-sliding-puzzle
0794-swim-in-rising-water
0854-making-a-large-island
1171-shortest-path-in-binary-matrix
1379-reconstruct-a-2-row-binary-matrix
1396-count-servers-that-communicate
1402-count-square-submatrices-with-all-ones
1753-path-with-minimum-effort
1972-rotating-the-box
2047-find-a-peak-element-ii
2343-count-unguarded-cells-in-the-grid
2375-minimum-obstacle-removal-to-reach-corner
2411-spiral-matrix-iv
2521-paths-in-matrix-whose-sum-is-divisible-by-k
2606-difference-between-ones-and-zeros-in-row-and-column
2685-first-completely-painted-row-or-column
2711-minimum-time-to-visit-a-cell-in-a-grid
3188-find-champion-i
3627-find-minimum-time-to-reach-last-room-i

Simulation

0054-spiral-matrix
0059-spiral-matrix-ii
0258-add-digits
0289-game-of-life
0566-reshape-the-matrix
0657-robot-return-to-origin
0987-reveal-cards-in-increasing-order
2048-build-array-from-permutation
2232-adding-spaces-to-a-string
2260-divide-a-string-into-groups-of-size-k
2265-partition-array-according-to-given-pivot
2343-count-unguarded-cells-in-the-grid
2411-spiral-matrix-iv
2551-apply-operations-to-an-array
2606-difference-between-ones-and-zeros-in-row-and-column
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
3332-minimum-operations-to-exceed-threshold-value-ii
3434-find-the-number-of-distinct-colors-among-the-balls
3447-clear-digits
3555-final-array-state-after-k-multiplication-operations-i
3790-fruits-into-baskets-ii

Hash Table

0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0037-sudoku-solver
0073-set-matrix-zeroes
0127-word-ladder
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0208-implement-trie-prefix-tree
0242-valid-anagram
0299-bulls-and-cows
0355-design-twitter
0383-ransom-note
0387-first-unique-character-in-a-string
0421-maximum-xor-of-two-numbers-in-an-array
0720-longest-word-in-dictionary
0721-accounts-merge
0837-most-common-word
0889-buddy-strings
0893-all-nodes-distance-k-in-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0931-maximum-frequency-stack
0952-word-subsets
1023-time-based-key-value-store
1160-letter-tile-possibilities
1207-delete-nodes-and-return-forest
1364-tuple-with-same-product
1387-find-elements-in-a-contaminated-binary-tree
1468-check-if-n-and-its-double-exist
1502-construct-k-palindrome-strings
1915-check-if-one-string-swap-can-make-strings-equal
2104-operations-on-tree
2107-find-unique-binary-string
2215-finding-3-digit-even-numbers
2270-find-all-lonely-numbers-in-the-array
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2429-design-a-food-rating-system
2434-design-a-number-container-system
2448-count-number-of-bad-pairs
2461-amount-of-time-for-binary-tree-to-be-infected
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2543-most-popular-video-creator
2640-maximum-number-of-integers-to-choose-from-a-range-i
2685-first-completely-painted-row-or-column
2695-find-score-of-an-array-after-marking-all-elements
2766-find-the-prefix-common-array-of-two-arrays
2831-number-of-beautiful-pairs
3242-count-elements-with-maximum-frequency
3360-minimum-deletions-to-make-string-k-special
3434-find-the-number-of-distinct-colors-among-the-balls
3445-lexicographically-minimum-string-after-removing-stars
3455-minimum-length-of-string-after-operations

String

0008-string-to-integer-atoi
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0038-count-and-say
0079-word-search
0087-scramble-string
0091-decode-ways
0127-word-ladder
0131-palindrome-partitioning
0132-palindrome-partitioning-ii
0151-reverse-words-in-a-string
0171-excel-sheet-column-number
0179-largest-number
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0242-valid-anagram
0273-integer-to-english-words
0297-serialize-and-deserialize-binary-tree
0299-bulls-and-cows
0383-ransom-note
0387-first-unique-character-in-a-string
0392-is-subsequence
0443-string-compression
0524-longest-word-in-dictionary-through-deleting
0556-next-greater-element-iii
0657-robot-return-to-origin
0720-longest-word-in-dictionary
0721-accounts-merge
0837-most-common-word
0868-push-dominoes
0889-buddy-strings
0952-word-subsets
0957-minimum-add-to-make-parentheses-valid
1023-time-based-key-value-store
1058-lexicographically-smallest-equivalent-string
1080-camelcase-matching
1093-recover-a-tree-from-preorder-traversal
1160-letter-tile-possibilities
1397-search-suggestions-system
1502-construct-k-palindrome-strings
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1714-rearrange-spaces-between-words
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
2093-check-if-string-is-a-prefix-of-array
2107-find-unique-binary-string
2221-check-if-a-parentheses-string-can-be-valid
2232-adding-spaces-to-a-string
2260-divide-a-string-into-groups-of-size-k
2292-counting-words-with-a-given-prefix
2341-count-prefixes-of-a-given-string
2427-first-letter-to-appear-twice
2456-construct-smallest-number-from-di-string
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2543-most-popular-video-creator
2691-count-vowel-strings-in-ranges
3018-make-string-a-subsequence-using-cyclic-increments
3019-furthest-point-from-origin
3194-find-words-containing-character
3305-count-prefix-and-suffix-pairs-ii
3309-count-prefix-and-suffix-pairs-i
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3451-string-compression-iii
3455-minimum-length-of-string-after-operations

Bit Manipulation

0078-subsets
0090-subsets-ii
0222-count-complete-tree-nodes
0371-sum-of-two-integers
0421-maximum-xor-of-two-numbers-in-an-array
0476-number-complement
0795-k-th-symbol-in-grammar
1054-complement-of-base-10-integer
1826-maximum-xor-with-an-element-from-array
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3246-check-if-bitwise-or-has-trailing-zeros
3508-number-of-bit-changes-to-make-two-integers-equal

Counting

0299-bulls-and-cows
0383-ransom-note
0387-first-unique-character-in-a-string
0837-most-common-word
1160-letter-tile-possibilities
1364-tuple-with-same-product
1396-count-servers-that-communicate
1502-construct-k-palindrome-strings
1915-check-if-one-string-swap-can-make-strings-equal
2270-find-all-lonely-numbers-in-the-array
2308-divide-array-into-equal-pairs
2427-first-letter-to-appear-twice
2448-count-number-of-bad-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
2831-number-of-beautiful-pairs
3019-furthest-point-from-origin
3242-count-elements-with-maximum-frequency
3360-minimum-deletions-to-make-string-k-special
3455-minimum-length-of-string-after-operations

Queue

0387-first-unique-character-in-a-string
0969-number-of-recent-calls
0987-reveal-cards-in-increasing-order

Database

0178-rank-scores
0184-department-highest-salary
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0602-friend-requests-ii-who-has-the-most-friends
0608-tree-node
0626-exchange-seats
1135-customers-who-bought-all-products
1155-product-sales-analysis-iii
1268-market-analysis-i
1327-last-person-to-fit-in-the-bus
1415-students-and-examinations
1480-movie-rating
1509-replace-employee-id-with-the-unique-identifier
1523-capital-gainloss
1541-top-travellers
2087-confirmation-rate
3530-odd-and-even-transactions
3816-dna-pattern-recognition

Two Pointers

0018-4sum
0031-next-permutation
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0295-find-median-from-data-stream
0392-is-subsequence
0443-string-compression
0524-longest-word-in-dictionary-through-deleting
0556-next-greater-element-iii
0611-valid-triangle-number
0633-sum-of-square-numbers
0868-push-dominoes
0908-middle-of-the-linked-list
1080-camelcase-matching
1468-check-if-n-and-its-double-exist
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1972-rotating-the-box
2093-check-if-string-is-a-prefix-of-array
2216-delete-the-middle-node-of-a-linked-list
2232-adding-spaces-to-a-string
2236-maximum-twin-sum-of-a-linked-list
2265-partition-array-according-to-given-pivot
2551-apply-operations-to-an-array
3018-make-string-a-subsequence-using-cyclic-increments

Graph

0744-network-delay-time
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
1300-critical-connections-in-a-network
1424-maximum-candies-you-can-get-from-boxes
1442-number-of-operations-to-make-network-connected
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2090-number-of-ways-to-arrive-at-destination
2375-minimum-obstacle-removal-to-reach-corner
2711-minimum-time-to-visit-a-cell-in-a-grid
3189-find-champion-ii
3627-find-minimum-time-to-reach-last-room-i

Sliding Window

1586-longest-subarray-of-1s-after-deleting-one-element
1755-defuse-the-bomb
1966-frequency-of-the-most-frequent-element
2463-minimum-recolors-to-get-k-consecutive-black-blocks

Binary Search

0004-median-of-two-sorted-arrays
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0222-count-complete-tree-nodes
0240-search-a-2d-matrix-ii
0300-longest-increasing-subsequence
0367-valid-perfect-square
0410-split-array-largest-sum
0493-reverse-pairs
0611-valid-triangle-number
0633-sum-of-square-numbers
0794-swim-in-rising-water
0907-koko-eating-bananas
1023-time-based-key-value-store
1056-capacity-to-ship-packages-within-d-days
1397-search-suggestions-system
1408-find-the-smallest-divisor-given-a-threshold
1468-check-if-n-and-its-double-exist
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
1753-path-with-minimum-effort
1966-frequency-of-the-most-frequent-element
2047-find-a-peak-element-ii
2591-frog-jump-ii
2614-maximum-count-of-positive-integer-and-negative-integer
2640-maximum-number-of-integers-to-choose-from-a-range-i
3790-fruits-into-baskets-ii

Union Find

0721-accounts-merge
0794-swim-in-rising-water
0854-making-a-large-island
1058-lexicographically-smallest-equivalent-string
1396-count-servers-that-communicate
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
3219-make-lexicographically-smallest-array-by-swapping-elements

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0295-find-median-from-data-stream
0355-design-twitter
0502-ipo
0506-relative-ranks
0744-network-delay-time
0789-kth-largest-element-in-a-stream
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
0948-sort-an-array
1127-last-stone-weight
1397-search-suggestions-system
1753-path-with-minimum-effort
1955-seat-reservation-manager
2094-remove-stones-to-minimize-the-total
2310-minimum-operations-to-halve-array-sum
2375-minimum-obstacle-removal-to-reach-corner
2429-design-a-food-rating-system
2434-design-a-number-container-system
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2543-most-popular-video-creator
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2711-minimum-time-to-visit-a-cell-in-a-grid
3332-minimum-operations-to-exceed-threshold-value-ii
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

Shortest Path

0744-network-delay-time
0803-cheapest-flights-within-k-stops
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2090-number-of-ways-to-arrive-at-destination
2375-minimum-obstacle-removal-to-reach-corner
2711-minimum-time-to-visit-a-cell-in-a-grid
3627-find-minimum-time-to-reach-last-room-i

Dynamic Programming

0022-generate-parentheses
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0085-maximal-rectangle
0087-scramble-string
0091-decode-ways
0119-pascals-triangle-ii
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0131-palindrome-partitioning
0132-palindrome-partitioning-ii
0152-maximum-product-subarray
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0213-house-robber-ii
0221-maximal-square
0300-longest-increasing-subsequence
0322-coin-change
0392-is-subsequence
0403-frog-jump
0410-split-array-largest-sum
0650-2-keys-keyboard
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0747-min-cost-climbing-stairs
0803-cheapest-flights-within-k-stops
0868-push-dominoes
1025-minimum-cost-for-tickets
1121-partition-array-for-maximum-sum
1402-count-square-submatrices-with-all-ones
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1586-longest-subarray-of-1s-after-deleting-one-element
1631-number-of-sub-arrays-with-odd-sum
1669-minimum-cost-to-cut-a-stick
2090-number-of-ways-to-arrive-at-destination
2521-paths-in-matrix-whose-sum-is-divisible-by-k

Topological Sort

0820-find-eventual-safe-states
2090-number-of-ways-to-arrive-at-destination

String Matching

1080-camelcase-matching
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
3305-count-prefix-and-suffix-pairs-ii
3309-count-prefix-and-suffix-pairs-i

Greedy

0122-best-time-to-buy-and-sell-stock-ii
0179-largest-number
0410-split-array-largest-sum
0502-ipo
0517-super-washing-machines
0611-valid-triangle-number
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0957-minimum-add-to-make-parentheses-valid
1379-reconstruct-a-2-row-binary-matrix
1502-construct-k-palindrome-strings
1529-max-difference-you-can-get-from-changing-an-integer
1966-frequency-of-the-most-frequent-element
2094-remove-stones-to-minimize-the-total
2221-check-if-a-parentheses-string-can-be-valid
2310-minimum-operations-to-halve-array-sum
2387-partition-array-such-that-maximum-difference-is-k
2456-construct-smallest-number-from-di-string
2509-minimize-xor
2591-frog-jump-ii
2640-maximum-number-of-integers-to-choose-from-a-range-i
2704-maximum-difference-by-remapping-a-digit
3241-divide-array-into-arrays-with-max-difference
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars

Sorting

0018-4sum
0088-merge-sorted-array
0179-largest-number
0215-kth-largest-element-in-an-array
0242-valid-anagram
0295-find-median-from-data-stream
0502-ipo
0506-relative-ranks
0524-longest-word-in-dictionary-through-deleting
0611-valid-triangle-number
0720-longest-word-in-dictionary
0721-accounts-merge
0948-sort-an-array
0987-reveal-cards-in-increasing-order
1397-search-suggestions-system
1468-check-if-n-and-its-double-exist
1669-minimum-cost-to-cut-a-stick
1966-frequency-of-the-most-frequent-element
2215-finding-3-digit-even-numbers
2387-partition-array-such-that-maximum-difference-is-k
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2543-most-popular-video-creator
2640-maximum-number-of-integers-to-choose-from-a-range-i
2695-find-score-of-an-array-after-marking-all-elements
3219-make-lexicographically-smallest-array-by-swapping-elements
3241-divide-array-into-arrays-with-max-difference
3360-minimum-deletions-to-make-string-k-special

Math

0002-add-two-numbers
0012-integer-to-roman
0013-roman-to-integer
0050-powx-n
0062-unique-paths
0069-sqrtx
0070-climbing-stairs
0171-excel-sheet-column-number
0204-count-primes
0258-add-digits
0273-integer-to-english-words
0367-valid-perfect-square
0371-sum-of-two-integers
0556-next-greater-element-iii
0633-sum-of-square-numbers
0650-2-keys-keyboard
0795-k-th-symbol-in-grammar
1421-find-numbers-with-even-number-of-digits
1477-product-of-the-last-k-numbers
1529-max-difference-you-can-get-from-changing-an-integer
1631-number-of-sub-arrays-with-odd-sum
1889-check-if-number-is-a-sum-of-powers-of-three
2050-count-good-numbers
2106-find-greatest-common-divisor-of-array
2448-count-number-of-bad-pairs
2507-number-of-common-factors
2704-maximum-difference-by-remapping-a-digit
2802-find-the-punishment-number-of-an-integer
2831-number-of-beautiful-pairs
3555-final-array-state-after-k-multiplication-operations-i

Divide and Conquer

0004-median-of-two-sorted-arrays
0108-convert-sorted-array-to-binary-search-tree
0215-kth-largest-element-in-an-array
0240-search-a-2d-matrix-ii
0493-reverse-pairs
0654-maximum-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0948-sort-an-array

Merge Sort

0493-reverse-pairs
0948-sort-an-array

Bucket Sort

0948-sort-an-array

Radix Sort

0948-sort-an-array

Counting Sort

0948-sort-an-array

Memoization

0070-climbing-stairs

Monotonic Stack

0085-maximal-rectangle
0654-maximum-binary-tree
1570-final-prices-with-a-special-discount-in-a-shop

Binary Search Tree

0098-validate-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0235-lowest-common-ancestor-of-a-binary-search-tree
0789-kth-largest-element-in-a-stream

Trie

0014-longest-common-prefix
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0421-maximum-xor-of-two-numbers-in-an-array
0720-longest-word-in-dictionary
1080-camelcase-matching
1397-search-suggestions-system
1826-maximum-xor-with-an-element-from-array
3305-count-prefix-and-suffix-pairs-ii
3309-count-prefix-and-suffix-pairs-i

Number Theory

0204-count-primes
0258-add-digits
2106-find-greatest-common-divisor-of-array
2507-number-of-common-factors
2831-number-of-beautiful-pairs

Recursion

0002-add-two-numbers
0025-reverse-nodes-in-k-group
0050-powx-n
0206-reverse-linked-list
0273-integer-to-english-words
0795-k-th-symbol-in-grammar
2050-count-good-numbers

Prefix Sum

0303-range-sum-query-immutable
0410-split-array-largest-sum
0724-find-pivot-index
1477-product-of-the-last-k-numbers
1631-number-of-sub-arrays-with-odd-sum
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1966-frequency-of-the-most-frequent-element
2358-number-of-ways-to-split-array
2691-count-vowel-strings-in-ranges

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0046-permutations
0078-subsets
0079-word-search
0090-subsets-ii
0113-path-sum-ii
0131-palindrome-partitioning
1160-letter-tile-possibilities
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1819-construct-the-lexicographically-largest-valid-sequence
2107-find-unique-binary-string
2456-construct-smallest-number-from-di-string
2802-find-the-punishment-number-of-an-integer

Rolling Hash

3305-count-prefix-and-suffix-pairs-ii
3309-count-prefix-and-suffix-pairs-i

Hash Function

3305-count-prefix-and-suffix-pairs-ii
3309-count-prefix-and-suffix-pairs-i

Brainteaser

2533-bitwise-xor-of-all-pairings

Combinatorics

0062-unique-paths

Ordered Set

0493-reverse-pairs
0931-maximum-frequency-stack
2429-design-a-food-rating-system
2434-design-a-number-container-system

Quickselect

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

Biconnected Component

1300-critical-connections-in-a-network

Enumeration

0204-count-primes
2215-finding-3-digit-even-numbers
2507-number-of-common-factors
3221-find-the-peaks

Segment Tree

0493-reverse-pairs
3790-fruits-into-baskets-ii

Binary Indexed Tree

0493-reverse-pairs