LeetCode-solutions

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

Array

0198-house-robber
0287-find-the-duplicate-number
0309-best-time-to-buy-and-sell-stock-with-cooldown
0416-partition-equal-subset-sum
0628-maximum-product-of-three-numbers
0747-min-cost-climbing-stairs
0883-car-fleet
2148-minimum-number-of-moves-to-seat-everyone

Math

0279-perfect-squares
0343-integer-break
0628-maximum-product-of-three-numbers

Sorting

0628-maximum-product-of-three-numbers
0883-car-fleet
2148-minimum-number-of-moves-to-seat-everyone

String

0424-longest-repeating-character-replacement
0567-permutation-in-string
1250-longest-common-subsequence

Dynamic Programming

0198-house-robber
0279-perfect-squares
0309-best-time-to-buy-and-sell-stock-with-cooldown
0343-integer-break
0416-partition-equal-subset-sum
0747-min-cost-climbing-stairs
1250-longest-common-subsequence

Greedy

2148-minimum-number-of-moves-to-seat-everyone

Linked List

0142-linked-list-cycle-ii
0143-reorder-list

Two Pointers

0142-linked-list-cycle-ii
0143-reorder-list
0287-find-the-duplicate-number
0567-permutation-in-string

Stack

0143-reorder-list
0883-car-fleet

Recursion

0143-reorder-list

Hash Table

0142-linked-list-cycle-ii
0424-longest-repeating-character-replacement
0567-permutation-in-string

Sliding Window

0424-longest-repeating-character-replacement
0567-permutation-in-string

Tree

0530-minimum-absolute-difference-in-bst

Depth-First Search

0530-minimum-absolute-difference-in-bst

Breadth-First Search

0279-perfect-squares
0530-minimum-absolute-difference-in-bst

Binary Search Tree

0287-find-the-duplicate-number
0530-minimum-absolute-difference-in-bst

Binary Tree

0530-minimum-absolute-difference-in-bst

Monotonic Stack

0883-car-fleet

Bit Manipulation

0287-find-the-duplicate-number

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0037-sudoku-solver
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0128-longest-consecutive-sequence
0133-clone-graph
0138-copy-list-with-random-pointer
0146-lru-cache
0169-majority-element
0202-happy-number
0219-contains-duplicate-ii
0242-valid-anagram
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0448-find-all-numbers-disappeared-in-an-array
0525-contiguous-array
0560-subarray-sum-equals-k
0621-task-scheduler
0690-employee-importance
0753-open-the-lock
0843-binary-trees-with-factors
0906-walking-robot-simulation
0929-unique-email-addresses
1256-rank-transform-of-an-array
1308-smallest-string-with-swaps
1556-make-two-arrays-equal-by-reversing-subarrays
1635-number-of-good-pairs
1715-split-a-string-into-the-max-number-of-unique-substrings
1741-sort-array-by-increasing-frequency
1866-restore-the-array-from-adjacent-pairs
1986-largest-color-value-in-a-directed-graph
2163-kth-distinct-string-in-an-array
2461-maximum-sum-of-distinct-subarrays-with-length-k
2586-longest-square-streak-in-an-array
2677-cousins-in-binary-tree-ii
3788-maximum-unique-subarray-sum-after-deletion

Depth-First Search

0098-validate-binary-search-tree
0104-maximum-depth-of-binary-tree
0112-path-sum
0133-clone-graph
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0417-pacific-atlantic-water-flow
0463-island-perimeter
0690-employee-importance
0695-max-area-of-island
0744-network-delay-time
0776-n-ary-tree-postorder-traversal
0801-is-graph-bipartite
0813-all-paths-from-source-to-target
0971-shortest-bridge
0988-flip-equivalent-binary-trees
1104-coloring-a-border
1308-smallest-string-with-swaps
1350-remove-sub-folders-from-the-filesystem
1448-count-good-nodes-in-binary-tree
1544-count-good-nodes-in-binary-tree
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
1663-detect-cycles-in-2d-grid
1753-path-with-minimum-effort
1866-restore-the-array-from-adjacent-pairs
2035-count-sub-islands
2545-height-of-binary-tree-after-subtree-removal-queries
2677-cousins-in-binary-tree-ii

Breadth-First Search

0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0133-clone-graph
0199-binary-tree-right-side-view
0279-perfect-squares
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0417-pacific-atlantic-water-flow
0463-island-perimeter
0690-employee-importance
0695-max-area-of-island
0744-network-delay-time
0753-open-the-lock
0787-sliding-puzzle
0801-is-graph-bipartite
0813-all-paths-from-source-to-target
0971-shortest-bridge
1036-rotting-oranges
1104-coloring-a-border
1229-shortest-path-with-alternating-colors
1308-smallest-string-with-swaps
1448-count-good-nodes-in-binary-tree
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1544-count-good-nodes-in-binary-tree
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
1663-detect-cycles-in-2d-grid
1753-path-with-minimum-effort
2035-count-sub-islands
2183-minimum-operations-to-convert-number
2545-height-of-binary-tree-after-subtree-removal-queries
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii

Graph

0133-clone-graph
0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
0744-network-delay-time
0801-is-graph-bipartite
0813-all-paths-from-source-to-target
1229-shortest-path-with-alternating-colors
1325-path-with-maximum-probability
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1576-reorder-routes-to-make-all-paths-lead-to-the-city-zero
1912-number-of-restricted-paths-from-first-to-last-node
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2176-parallel-courses-iii

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0037-sudoku-solver
0039-combination-sum
0046-permutations
0047-permutations-ii
0051-n-queens
0053-maximum-subarray
0055-jump-game
0056-merge-intervals
0057-insert-interval
0063-unique-paths-ii
0066-plus-one
0078-subsets
0080-remove-duplicates-from-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
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
0128-longest-consecutive-sequence
0136-single-number
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0174-dungeon-game
0198-house-robber
0209-minimum-size-subarray-sum
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0219-contains-duplicate-ii
0221-maximal-square
0252-meeting-rooms
0253-meeting-rooms-ii
0283-move-zeroes
0300-longest-increasing-subsequence
0303-range-sum-query-immutable
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0329-longest-increasing-path-in-a-matrix
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0377-combination-sum-iv
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0435-non-overlapping-intervals
0436-find-right-interval
0448-find-all-numbers-disappeared-in-an-array
0463-island-perimeter
0475-heaters
0494-target-sum
0498-diagonal-traverse
0518-coin-change-ii
0525-contiguous-array
0560-subarray-sum-equals-k
0581-shortest-unsorted-continuous-subarray
0611-valid-triangle-number
0621-task-scheduler
0690-employee-importance
0695-max-area-of-island
0747-min-cost-climbing-stairs
0753-open-the-lock
0759-employee-free-time
0787-sliding-puzzle
0790-global-and-local-inversions
0792-binary-search
0843-binary-trees-with-factors
0853-most-profit-assigning-work
0859-design-circular-deque
0883-car-fleet
0906-walking-robot-simulation
0929-unique-email-addresses
0954-maximum-sum-circular-subarray
0967-minimum-falling-path-sum
0971-shortest-bridge
0989-add-to-array-form-of-integer
1019-squares-of-a-sorted-array
1036-rotting-oranges
1046-max-consecutive-ones-iii
1047-maximize-sum-of-array-after-k-negations
1104-coloring-a-border
1121-partition-array-for-maximum-sum
1196-filling-bookcase-shelves
1256-rank-transform-of-an-array
1306-minimum-absolute-difference
1308-smallest-string-with-swaps
1325-path-with-maximum-probability
1350-remove-sub-folders-from-the-filesystem
1367-maximum-height-by-stacking-cuboids
1402-count-square-submatrices-with-all-ones
1408-find-the-smallest-divisor-given-a-threshold
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1528-kids-with-the-greatest-number-of-candies
1556-make-two-arrays-equal-by-reversing-subarrays
1605-minimum-number-of-days-to-make-m-bouquets
1635-number-of-good-pairs
1663-detect-cycles-in-2d-grid
1669-minimum-cost-to-cut-a-stick
1741-sort-array-by-increasing-frequency
1753-path-with-minimum-effort
1766-minimum-number-of-removals-to-make-mountain-array
1849-maximum-absolute-sum-of-any-subarray
1866-restore-the-array-from-adjacent-pairs
1929-concatenation-of-array
1940-maximum-xor-for-each-query
2006-find-the-student-that-will-replace-the-chalk
2016-reduction-operations-to-make-the-array-elements-equal
2035-count-sub-islands
2049-eliminate-maximum-number-of-monsters
2058-concatenation-of-array
2132-convert-1d-array-into-2d-array
2144-maximum-difference-between-increasing-elements
2155-find-missing-observations
2163-kth-distinct-string-in-an-array
2170-count-number-of-maximum-bitwise-or-subsets
2176-parallel-courses-iii
2179-most-beautiful-item-for-each-query
2183-minimum-operations-to-convert-number
2267-minimum-difference-in-sums-after-removal-of-elements
2461-maximum-sum-of-distinct-subarrays-with-length-k
2545-height-of-binary-tree-after-subtree-removal-queries
2554-minimum-total-distance-traveled
2586-longest-square-streak-in-an-array
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2794-maximum-number-of-moves-in-a-grid
3194-find-words-containing-character
3251-maximum-area-of-longest-diagonal-rectangle
3291-find-if-array-can-be-sorted
3380-shortest-subarray-with-or-at-least-k-ii
3476-find-minimum-operations-to-make-all-elements-divisible-by-three
3491-find-the-maximum-length-of-valid-subsequence-ii
3522-find-the-power-of-k-size-subarrays-i
3788-maximum-unique-subarray-sum-after-deletion
3790-fruits-into-baskets-ii

Dynamic Programming

0005-longest-palindromic-substring
0053-maximum-subarray
0055-jump-game
0063-unique-paths-ii
0072-edit-distance
0091-decode-ways
0121-best-time-to-buy-and-sell-stock
0174-dungeon-game
0198-house-robber
0213-house-robber-ii
0221-maximal-square
0279-perfect-squares
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0329-longest-increasing-path-in-a-matrix
0377-combination-sum-iv
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0576-out-of-boundary-paths
0678-valid-parenthesis-string
0747-min-cost-climbing-stairs
0787-sliding-puzzle
0843-binary-trees-with-factors
0954-maximum-sum-circular-subarray
0967-minimum-falling-path-sum
1013-fibonacci-number
1121-partition-array-for-maximum-sum
1196-filling-bookcase-shelves
1250-longest-common-subsequence
1263-number-of-dice-rolls-with-target-sum
1367-maximum-height-by-stacking-cuboids
1402-count-square-submatrices-with-all-ones
1437-minimum-insertion-steps-to-make-a-string-palindrome
1669-minimum-cost-to-cut-a-stick
1766-minimum-number-of-removals-to-make-mountain-array
1849-maximum-absolute-sum-of-any-subarray
1912-number-of-restricted-paths-from-first-to-last-node
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2176-parallel-courses-iii
2267-minimum-difference-in-sums-after-removal-of-elements
2554-minimum-total-distance-traveled
2586-longest-square-streak-in-an-array
2794-maximum-number-of-moves-in-a-grid
3491-find-the-maximum-length-of-valid-subsequence-ii

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0020-valid-parentheses
0067-add-binary
0072-edit-distance
0091-decode-ways
0242-valid-anagram
0412-fizz-buzz
0415-add-strings
0516-longest-palindromic-subsequence
0592-fraction-addition-and-subtraction
0678-valid-parenthesis-string
0753-open-the-lock
0812-rotate-string
0929-unique-email-addresses
1146-greatest-common-divisor-of-strings
1197-parsing-a-boolean-expression
1205-defanging-an-ip-address
1249-minimum-remove-to-make-valid-parentheses
1250-longest-common-subsequence
1302-delete-characters-to-make-fancy-string
1308-smallest-string-with-swaps
1350-remove-sub-folders-from-the-filesystem
1437-minimum-insertion-steps-to-make-a-string-palindrome
1667-find-kth-bit-in-nth-binary-string
1715-split-a-string-into-the-max-number-of-unique-substrings
1894-merge-strings-alternately
2076-sum-of-digits-of-string-after-convert
2095-minimum-number-of-swaps-to-make-the-string-balanced
2163-kth-distinct-string-in-an-array
2260-divide-a-string-into-groups-of-size-k
2580-circular-sentence
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3194-find-words-containing-character
3451-string-compression-iii

Sorting

0015-3sum
0056-merge-intervals
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0242-valid-anagram
0252-meeting-rooms
0253-meeting-rooms-ii
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0435-non-overlapping-intervals
0436-find-right-interval
0475-heaters
0581-shortest-unsorted-continuous-subarray
0611-valid-triangle-number
0621-task-scheduler
0759-employee-free-time
0843-binary-trees-with-factors
0853-most-profit-assigning-work
0883-car-fleet
1019-squares-of-a-sorted-array
1047-maximize-sum-of-array-after-k-negations
1256-rank-transform-of-an-array
1306-minimum-absolute-difference
1308-smallest-string-with-swaps
1367-maximum-height-by-stacking-cuboids
1556-make-two-arrays-equal-by-reversing-subarrays
1669-minimum-cost-to-cut-a-stick
1741-sort-array-by-increasing-frequency
2016-reduction-operations-to-make-the-array-elements-equal
2049-eliminate-maximum-number-of-monsters
2179-most-beautiful-item-for-each-query
2554-minimum-total-distance-traveled
2586-longest-square-streak-in-an-array
2646-kth-largest-sum-in-a-binary-tree
2699-count-the-number-of-fair-pairs
3291-find-if-array-can-be-sorted

Tree

0098-validate-binary-search-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0112-path-sum
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0690-employee-importance
0776-n-ary-tree-postorder-traversal
0988-flip-equivalent-binary-trees
1448-count-good-nodes-in-binary-tree
1544-count-good-nodes-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

Binary Tree

0098-validate-binary-search-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0112-path-sum
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0988-flip-equivalent-binary-trees
1448-count-good-nodes-in-binary-tree
1544-count-good-nodes-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

Matrix

0037-sudoku-solver
0063-unique-paths-ii
0174-dungeon-game
0221-maximal-square
0329-longest-increasing-path-in-a-matrix
0417-pacific-atlantic-water-flow
0463-island-perimeter
0498-diagonal-traverse
0695-max-area-of-island
0787-sliding-puzzle
0967-minimum-falling-path-sum
0971-shortest-bridge
1036-rotting-oranges
1104-coloring-a-border
1402-count-square-submatrices-with-all-ones
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1663-detect-cycles-in-2d-grid
1753-path-with-minimum-effort
2035-count-sub-islands
2132-convert-1d-array-into-2d-array
2794-maximum-number-of-moves-in-a-grid

Greedy

0011-container-with-most-water
0055-jump-game
0253-meeting-rooms-ii
0435-non-overlapping-intervals
0581-shortest-unsorted-continuous-subarray
0611-valid-triangle-number
0621-task-scheduler
0670-maximum-swap
0678-valid-parenthesis-string
0853-most-profit-assigning-work
1047-maximize-sum-of-array-after-k-negations
1766-minimum-number-of-removals-to-make-mountain-array
2049-eliminate-maximum-number-of-monsters
2095-minimum-number-of-swaps-to-make-the-string-balanced
2716-prime-subtraction-operation
3788-maximum-unique-subarray-sum-after-deletion

Counting

0169-majority-element
0621-task-scheduler
1635-number-of-good-pairs
1986-largest-color-value-in-a-directed-graph
2163-kth-distinct-string-in-an-array

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0167-two-sum-ii-input-array-is-sorted
0202-happy-number
0253-meeting-rooms-ii
0283-move-zeroes
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0475-heaters
0581-shortest-unsorted-continuous-subarray
0611-valid-triangle-number
0853-most-profit-assigning-work
1019-squares-of-a-sorted-array
1894-merge-strings-alternately
2095-minimum-number-of-swaps-to-make-the-string-balanced
2699-count-the-number-of-fair-pairs

Backtracking

0037-sudoku-solver
0039-combination-sum
0046-permutations
0047-permutations-ii
0051-n-queens
0077-combinations
0078-subsets
0494-target-sum
0787-sliding-puzzle
0813-all-paths-from-source-to-target
1715-split-a-string-into-the-max-number-of-unique-substrings
2170-count-number-of-maximum-bitwise-or-subsets

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0253-meeting-rooms-ii
0621-task-scheduler
0744-network-delay-time
0759-employee-free-time
1325-path-with-maximum-probability
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1753-path-with-minimum-effort
1912-number-of-restricted-paths-from-first-to-last-node
2267-minimum-difference-in-sums-after-removal-of-elements

Bit Manipulation

0067-add-binary
0078-subsets
0136-single-number
0222-count-complete-tree-nodes
1940-maximum-xor-for-each-query
2170-count-number-of-maximum-bitwise-or-subsets
2837-minimum-operations-to-make-the-integer-zero
3291-find-if-array-can-be-sorted
3380-shortest-subarray-with-or-at-least-k-ii
3394-minimum-array-end

Simulation

0067-add-binary
0412-fizz-buzz
0415-add-strings
0498-diagonal-traverse
0592-fraction-addition-and-subtraction
0906-walking-robot-simulation
1667-find-kth-bit-in-nth-binary-string
1929-concatenation-of-array
2006-find-the-student-that-will-replace-the-chalk
2058-concatenation-of-array
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2260-divide-a-string-into-groups-of-size-k
2288-count-operations-to-obtain-zero
3790-fruits-into-baskets-ii

Math

0002-add-two-numbers
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0202-happy-number
0279-perfect-squares
0412-fizz-buzz
0415-add-strings
0441-arranging-coins
0592-fraction-addition-and-subtraction
0668-kth-smallest-number-in-multiplication-table
0670-maximum-swap
0790-global-and-local-inversions
0989-add-to-array-form-of-integer
1013-fibonacci-number
1146-greatest-common-divisor-of-strings
1635-number-of-good-pairs
2155-find-missing-observations
2288-count-operations-to-obtain-zero
2556-convert-the-temperature
2716-prime-subtraction-operation
3172-divisible-and-non-divisible-sums-difference
3476-find-minimum-operations-to-make-all-elements-divisible-by-three

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0050-powx-n
1013-fibonacci-number
1197-parsing-a-boolean-expression
1667-find-kth-bit-in-nth-binary-string

Stack

0020-valid-parentheses
0084-largest-rectangle-in-histogram
0145-binary-tree-postorder-traversal
0155-min-stack
0581-shortest-unsorted-continuous-subarray
0678-valid-parenthesis-string
0776-n-ary-tree-postorder-traversal
0883-car-fleet
1197-parsing-a-boolean-expression
1249-minimum-remove-to-make-valid-parentheses
2095-minimum-number-of-swaps-to-make-the-string-balanced

Monotonic Stack

0084-largest-rectangle-in-histogram
0581-shortest-unsorted-continuous-subarray
0883-car-fleet

Shortest Path

0744-network-delay-time
1325-path-with-maximum-probability
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1912-number-of-restricted-paths-from-first-to-last-node
2090-number-of-ways-to-arrive-at-destination

Union Find

0128-longest-consecutive-sequence
0695-max-area-of-island
0801-is-graph-bipartite
1308-smallest-string-with-swaps
1663-detect-cycles-in-2d-grid
1753-path-with-minimum-effort
2035-count-sub-islands

Binary Search

0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0300-longest-increasing-subsequence
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0436-find-right-interval
0441-arranging-coins
0475-heaters
0611-valid-triangle-number
0668-kth-smallest-number-in-multiplication-table
0792-binary-search
0853-most-profit-assigning-work
1046-max-consecutive-ones-iii
1408-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
1753-path-with-minimum-effort
1766-minimum-number-of-removals-to-make-mountain-array
2006-find-the-student-that-will-replace-the-chalk
2179-most-beautiful-item-for-each-query
2586-longest-square-streak-in-an-array
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
3790-fruits-into-baskets-ii

Prefix Sum

0209-minimum-size-subarray-sum
0253-meeting-rooms-ii
0303-range-sum-query-immutable
0525-contiguous-array
0560-subarray-sum-equals-k
1046-max-consecutive-ones-iii
1940-maximum-xor-for-each-query
2006-find-the-student-that-will-replace-the-chalk

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0138-copy-list-with-random-pointer
0146-lru-cache
0859-design-circular-deque

Divide and Conquer

0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0169-majority-element
0215-kth-largest-element-in-an-array
0954-maximum-sum-circular-subarray

Merge Sort

0023-merge-k-sorted-lists

Binary Search Tree

0098-validate-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree

Design

0146-lru-cache
0155-min-stack
0303-range-sum-query-immutable
0859-design-circular-deque

Doubly-Linked List

0146-lru-cache

Queue

0859-design-circular-deque
0954-maximum-sum-circular-subarray

Topological Sort

0310-minimum-height-trees
0329-longest-increasing-path-in-a-matrix
1912-number-of-restricted-paths-from-first-to-last-node
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2176-parallel-courses-iii

Enumeration

2170-count-number-of-maximum-bitwise-or-subsets
2837-minimum-operations-to-make-the-integer-zero

Trie

0014-longest-common-prefix
1350-remove-sub-folders-from-the-filesystem

String Matching

0812-rotate-string

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
1046-max-consecutive-ones-iii
2461-maximum-sum-of-distinct-subarrays-with-length-k
3380-shortest-subarray-with-or-at-least-k-ii
3522-find-the-power-of-k-size-subarrays-i

Number Theory

2716-prime-subtraction-operation

Memoization

0329-longest-increasing-path-in-a-matrix
0787-sliding-puzzle
1013-fibonacci-number
1986-largest-color-value-in-a-directed-graph

Monotonic Queue

0954-maximum-sum-circular-subarray

Segment Tree

3790-fruits-into-baskets-ii

Ordered Set

3790-fruits-into-baskets-ii

Brainteaser

2837-minimum-operations-to-make-the-integer-zero

Quickselect

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

Sweep Line

0759-employee-free-time