leetcode-solutions

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

LeetCode Topics

String

0003-longest-substring-without-repeating-characters
0010-regular-expression-matching
0030-substring-with-concatenation-of-all-words
0032-longest-valid-parentheses
0038-count-and-say
0044-wildcard-matching
0049-group-anagrams
0065-valid-number
0072-edit-distance
0076-minimum-window-substring
0097-interleaving-string
0115-distinct-subsequences
0126-word-ladder-ii
0132-palindrome-partitioning-ii
0165-compare-version-numbers
0166-fraction-to-recurring-decimal
0179-largest-number
0301-remove-invalid-parentheses
0385-mini-parser
0420-strong-password-checker
0648-replace-words
0664-strange-printer
0686-repeated-string-match
0745-prefix-and-suffix-search
0921-minimum-add-to-make-parentheses-valid
1106-parsing-a-boolean-expression
1143-longest-common-subsequence
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1545-find-kth-bit-in-nth-binary-string
1639-number-of-ways-to-form-a-target-string-given-a-dictionary
1771-maximize-palindrome-length-from-subsequences
1813-sentence-similarity-iii
1871-palindrome-partitioning-iv
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
1930-unique-length-3-palindromic-subsequences
1980-find-unique-binary-string
2227-encrypt-and-decrypt-strings
2389-design-a-text-editor
2486-append-characters-to-string-to-make-subsequence
2487-optimal-partition-of-string
2669-find-the-substring-with-maximum-cost
3462-vowels-game-in-a-string
3598-longest-common-prefix-between-adjacent-strings-after-removals
3713-longest-balanced-substring-i
3760-maximum-substrings-with-distinct-start

Dynamic Programming

0010-regular-expression-matching
0032-longest-valid-parentheses
0042-trapping-rain-water
0044-wildcard-matching
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0063-unique-paths-ii
0064-minimum-path-sum
0072-edit-distance
0085-maximal-rectangle
0096-unique-binary-search-trees
0097-interleaving-string
0115-distinct-subsequences
0123-best-time-to-buy-and-sell-stock-iii
0124-binary-tree-maximum-path-sum
0132-palindrome-partitioning-ii
0152-maximum-product-subarray
0174-dungeon-game
0188-best-time-to-buy-and-sell-stock-iv
0233-number-of-digit-one
0264-ugly-number-ii
0300-longest-increasing-subsequence
0312-burst-balloons
0329-longest-increasing-path-in-a-matrix
0354-russian-doll-envelopes
0375-guess-number-higher-or-lower-ii
0376-wiggle-subsequence
0377-combination-sum-iv
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0446-arithmetic-slices-ii-subsequence
0552-student-attendance-record-ii
0600-non-negative-integers-without-consecutive-ones
0664-strange-printer
0769-largest-plus-sign
0799-champagne-tower
0803-cheapest-flights-within-k-stops
0805-split-array-with-same-average
0871-minimum-number-of-refueling-stops
0877-shortest-path-visiting-all-nodes
1143-longest-common-subsequence
1406-stone-game-iii
1458-max-dot-product-of-two-subsequences
1524-number-of-sub-arrays-with-odd-sum
1526-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1594-maximum-non-negative-product-in-a-matrix
1639-number-of-ways-to-form-a-target-string-given-a-dictionary
1771-maximize-palindrome-length-from-subsequences
1871-palindrome-partitioning-iv
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
1916-count-ways-to-build-rooms-in-an-ant-colony
1976-number-of-ways-to-arrive-at-destination
2035-partition-array-into-two-arrays-to-minimize-sum-difference
2669-find-the-substring-with-maximum-cost
2673-make-costs-of-paths-equal-in-a-binary-tree
3409-longest-subsequence-with-decreasing-adjacent-difference
4041-climbing-stairs-ii

Array

0011-container-with-most-water
0016-3sum-closest
0027-remove-element
0037-sudoku-solver
0041-first-missing-positive
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0048-rotate-image
0049-group-anagrams
0051-n-queens
0053-maximum-subarray
0055-jump-game
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0123-best-time-to-buy-and-sell-stock-iii
0128-longest-consecutive-sequence
0130-surrounded-regions
0135-candy
0137-single-number-ii
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0174-dungeon-game
0179-largest-number
0188-best-time-to-buy-and-sell-stock-iv
0200-number-of-islands
0209-minimum-size-subarray-sum
0218-the-skyline-problem
0220-contains-duplicate-iii
0229-majority-element-ii
0239-sliding-window-maximum
0260-single-number-iii
0275-h-index-ii
0284-peeking-iterator
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0312-burst-balloons
0327-count-of-range-sum
0329-longest-increasing-path-in-a-matrix
0330-patching-array
0354-russian-doll-envelopes
0373-find-k-pairs-with-smallest-sums
0376-wiggle-subsequence
0377-combination-sum-iv
0381-insert-delete-getrandom-o1-duplicates-allowed
0410-split-array-largest-sum
0416-partition-equal-subset-sum
0446-arithmetic-slices-ii-subsequence
0452-minimum-number-of-arrows-to-burst-balloons
0462-minimum-moves-to-equal-array-elements-ii
0480-sliding-window-median
0517-super-washing-machines
0528-random-pick-with-weight
0540-single-element-in-a-sorted-array
0621-task-scheduler
0624-maximum-distance-in-arrays
0630-course-schedule-iii
0632-smallest-range-covering-elements-from-k-lists
0648-replace-words
0659-split-array-into-consecutive-subsequences
0699-falling-squares
0745-prefix-and-suffix-search
0768-max-chunks-to-make-sorted-ii
0769-largest-plus-sign
0769-max-chunks-to-make-sorted
0795-number-of-subarrays-with-bounded-maximum
0798-transform-to-chessboard
0805-split-array-with-same-average
0828-chalkboard-xor-game
0846-hand-of-straights
0871-minimum-number-of-refueling-stops
0954-array-of-doubled-pairs
0995-minimum-number-of-k-consecutive-bit-flips
1029-two-city-scheduling
1052-grumpy-bookstore-owner
1074-number-of-submatrices-that-sum-to-target
1383-maximum-performance-of-a-team
1406-stone-game-iii
1428-jump-game-iii
1458-max-dot-product-of-two-subsequences
1491-number-of-times-binary-string-is-prefix-aligned
1524-number-of-sub-arrays-with-odd-sum
1526-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1552-magnetic-force-between-two-balls
1594-maximum-non-negative-product-in-a-matrix
1627-graph-connectivity-with-threshold
1631-path-with-minimum-effort
1639-number-of-ways-to-form-a-target-string-given-a-dictionary
1727-largest-submatrix-with-rearrangements
1793-maximum-score-of-a-good-subarray
1813-sentence-similarity-iii
1877-minimize-maximum-pair-sum-in-array
1891-count-pairs-of-nodes
1895-largest-magic-square
1916-count-ways-to-build-rooms-in-an-ant-colony
1980-find-unique-binary-string
2035-partition-array-into-two-arrays-to-minimize-sum-difference
2132-stamping-the-grid
2155-all-divisions-with-the-highest-score-of-a-binary-array
2211-k-radius-subarray-averages
2227-encrypt-and-decrypt-strings
2234-maximum-total-beauty-of-the-gardens
2437-maximum-number-of-groups-entering-a-competition
2488-count-subarrays-with-median-k
2661-first-completely-painted-row-or-column
2669-find-the-substring-with-maximum-cost
2673-maximize-win-from-two-segments
2673-make-costs-of-paths-equal-in-a-binary-tree
2679-sum-in-a-matrix
2779-maximum-beauty-of-an-array-after-applying-operation
2906-construct-product-matrix
2943-maximize-area-of-square-hole-in-grid
3047-find-the-largest-area-of-square-inside-two-rectangles
3049-earliest-second-to-mark-indices-ii
3067-count-pairs-of-connectable-servers-in-a-weighted-tree-network
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3212-count-submatrices-with-equal-frequency-of-x-and-y
3266-final-array-state-after-k-multiplication-operations-ii
3409-longest-subsequence-with-decreasing-adjacent-difference
3420-find-occurrences-of-an-element-in-an-array
3453-separate-squares-i
3546-equal-sum-grid-partition-i
3548-equal-sum-grid-partition-ii
3587-minimum-adjacent-swaps-to-alternate-parity
3598-longest-common-prefix-between-adjacent-strings-after-removals
3611-construct-the-minimum-bitwise-array-ii
3620-maximum-number-of-distinct-elements-after-operations
3625-count-number-of-trapezoids-ii
3627-maximum-median-sum-of-subsequences-of-size-3
3689-maximum-total-subarray-value-i
3719-longest-balanced-subarray-i
3739-count-subarrays-with-majority-element-ii
3741-minimum-distance-between-three-equal-elements-ii
3795-minimum-subarray-length-with-distinct-sum-at-least-k
4000-count-bowl-subarrays
4041-climbing-stairs-ii

Two Pointers

0011-container-with-most-water
0016-3sum-closest
0027-remove-element
0042-trapping-rain-water
0082-remove-duplicates-from-sorted-list-ii
0165-compare-version-numbers
0287-find-the-duplicate-number
0528-swapping-nodes-in-a-linked-list
0795-number-of-subarrays-with-bounded-maximum
1793-maximum-score-of-a-good-subarray
1813-sentence-similarity-iii
1877-minimize-maximum-pair-sum-in-array
1891-count-pairs-of-nodes
2035-partition-array-into-two-arrays-to-minimize-sum-difference
2234-maximum-total-beauty-of-the-gardens
2486-append-characters-to-string-to-make-subsequence

Stack

0032-longest-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0114-flatten-binary-tree-to-linked-list
0150-evaluate-reverse-polish-notation
0341-flatten-nested-list-iterator
0385-mini-parser
0768-max-chunks-to-make-sorted-ii
0769-max-chunks-to-make-sorted
0921-minimum-add-to-make-parentheses-valid
1106-parsing-a-boolean-expression
1526-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1793-maximum-score-of-a-good-subarray
2389-design-a-text-editor
4000-count-bowl-subarrays

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0768-max-chunks-to-make-sorted-ii
0769-max-chunks-to-make-sorted
1526-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1793-maximum-score-of-a-good-subarray
4000-count-bowl-subarrays

Hash Table

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0037-sudoku-solver
0041-first-missing-positive
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0126-word-ladder-ii
0128-longest-consecutive-sequence
0146-lru-cache
0149-max-points-on-a-line
0166-fraction-to-recurring-decimal
0229-majority-element-ii
0264-ugly-number-ii
0381-insert-delete-getrandom-o1-duplicates-allowed
0398-random-pick-index
0432-all-oone-data-structure
0480-sliding-window-median
0621-task-scheduler
0632-smallest-range-covering-elements-from-k-lists
0648-replace-words
0659-split-array-into-consecutive-subsequences
0745-prefix-and-suffix-search
0846-hand-of-straights
0954-array-of-doubled-pairs
1074-number-of-submatrices-that-sum-to-target
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1891-count-pairs-of-nodes
1930-unique-length-3-palindromic-subsequences
1980-find-unique-binary-string
2227-encrypt-and-decrypt-strings
2487-optimal-partition-of-string
2488-count-subarrays-with-median-k
2661-first-completely-painted-row-or-column
2669-find-the-substring-with-maximum-cost
3420-find-occurrences-of-an-element-in-an-array
3548-equal-sum-grid-partition-ii
3625-count-number-of-trapezoids-ii
3713-longest-balanced-substring-i
3719-longest-balanced-subarray-i
3739-count-subarrays-with-majority-element-ii
3741-minimum-distance-between-three-equal-elements-ii
3760-maximum-substrings-with-distinct-start
3795-minimum-subarray-length-with-distinct-sum-at-least-k

Greedy

0011-container-with-most-water
0044-wildcard-matching
0045-jump-game-ii
0055-jump-game
0135-candy
0179-largest-number
0330-patching-array
0376-wiggle-subsequence
0410-split-array-largest-sum
0420-strong-password-checker
0452-minimum-number-of-arrows-to-burst-balloons
0517-super-washing-machines
0621-task-scheduler
0624-maximum-distance-in-arrays
0630-course-schedule-iii
0632-smallest-range-covering-elements-from-k-lists
0659-split-array-into-consecutive-subsequences
0768-max-chunks-to-make-sorted-ii
0769-max-chunks-to-make-sorted
0770-couples-holding-hands
0846-hand-of-straights
0871-minimum-number-of-refueling-stops
0921-minimum-add-to-make-parentheses-valid
0954-array-of-doubled-pairs
1029-two-city-scheduling
1383-maximum-performance-of-a-team
1526-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1529-max-difference-you-can-get-from-changing-an-integer
1727-largest-submatrix-with-rearrangements
1802-maximum-value-at-a-given-index-in-a-bounded-array
1877-minimize-maximum-pair-sum-in-array
2132-stamping-the-grid
2234-maximum-total-beauty-of-the-gardens
2437-maximum-number-of-groups-entering-a-competition
2486-append-characters-to-string-to-make-subsequence
2487-optimal-partition-of-string
2673-make-costs-of-paths-equal-in-a-binary-tree
3049-earliest-second-to-mark-indices-ii
3587-minimum-adjacent-swaps-to-alternate-parity
3620-maximum-number-of-distinct-elements-after-operations
3627-maximum-median-sum-of-subsequences-of-size-3
3689-maximum-total-subarray-value-i

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0220-contains-duplicate-iii
0239-sliding-window-maximum
0480-sliding-window-median
0632-smallest-range-covering-elements-from-k-lists
0995-minimum-number-of-k-consecutive-bit-flips
1052-grumpy-bookstore-owner
1888-minimum-number-of-flips-to-make-the-binary-string-alternating
2211-k-radius-subarray-averages
2673-maximize-win-from-two-segments
2779-maximum-beauty-of-an-array-after-applying-operation
3795-minimum-subarray-length-with-distinct-sum-at-least-k

Sorting

0016-3sum-closest
0049-group-anagrams
0179-largest-number
0220-contains-duplicate-iii
0229-majority-element-ii
0354-russian-doll-envelopes
0452-minimum-number-of-arrows-to-burst-balloons
0462-minimum-moves-to-equal-array-elements-ii
0621-task-scheduler
0630-course-schedule-iii
0632-smallest-range-covering-elements-from-k-lists
0768-max-chunks-to-make-sorted-ii
0769-max-chunks-to-make-sorted
0846-hand-of-straights
0954-array-of-doubled-pairs
1029-two-city-scheduling
1383-maximum-performance-of-a-team
1552-magnetic-force-between-two-balls
1727-largest-submatrix-with-rearrangements
1877-minimize-maximum-pair-sum-in-array
1891-count-pairs-of-nodes
2234-maximum-total-beauty-of-the-gardens
2679-sum-in-a-matrix
2779-maximum-beauty-of-an-array-after-applying-operation
2943-maximize-area-of-square-hole-in-grid
3620-maximum-number-of-distinct-elements-after-operations
3627-maximum-median-sum-of-subsequences-of-size-3

Heap (Priority Queue)

0023-merge-k-sorted-lists
0218-the-skyline-problem
0239-sliding-window-maximum
0264-ugly-number-ii
0373-find-k-pairs-with-smallest-sums
0420-strong-password-checker
0480-sliding-window-median
0621-task-scheduler
0630-course-schedule-iii
0632-smallest-range-covering-elements-from-k-lists
0659-split-array-into-consecutive-subsequences
0803-cheapest-flights-within-k-stops
0871-minimum-number-of-refueling-stops
0885-exam-room
1383-maximum-performance-of-a-team
1631-path-with-minimum-effort
2679-sum-in-a-matrix
3049-earliest-second-to-mark-indices-ii
3266-final-array-state-after-k-multiplication-operations-ii

Backtracking

0037-sudoku-solver
0046-permutations
0051-n-queens
0052-n-queens-ii
0113-path-sum-ii
0126-word-ladder-ii
0301-remove-invalid-parentheses
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1980-find-unique-binary-string

Matrix

0037-sudoku-solver
0048-rotate-image
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0085-maximal-rectangle
0130-surrounded-regions
0174-dungeon-game
0200-number-of-islands
0329-longest-increasing-path-in-a-matrix
0798-transform-to-chessboard
1074-number-of-submatrices-that-sum-to-target
1594-maximum-non-negative-product-in-a-matrix
1631-path-with-minimum-effort
1727-largest-submatrix-with-rearrangements
1895-largest-magic-square
2132-stamping-the-grid
2661-first-completely-painted-row-or-column
2679-sum-in-a-matrix
2906-construct-product-matrix
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3212-count-submatrices-with-equal-frequency-of-x-and-y
3546-equal-sum-grid-partition-i
3548-equal-sum-grid-partition-ii

Math

0029-divide-two-integers
0048-rotate-image
0060-permutation-sequence
0096-unique-binary-search-trees
0149-max-points-on-a-line
0150-evaluate-reverse-polish-notation
0166-fraction-to-recurring-decimal
0172-factorial-trailing-zeroes
0233-number-of-digit-one
0264-ugly-number-ii
0319-bulb-switcher
0375-guess-number-higher-or-lower-ii
0381-insert-delete-getrandom-o1-duplicates-allowed
0398-random-pick-index
0462-minimum-moves-to-equal-array-elements-ii
0528-random-pick-with-weight
0780-reaching-points
0798-transform-to-chessboard
0805-split-array-with-same-average
0828-chalkboard-xor-game
1406-stone-game-iii
1524-number-of-sub-arrays-with-odd-sum
1529-max-difference-you-can-get-from-changing-an-integer
1622-fancy-sequence
1627-graph-connectivity-with-threshold
1802-maximum-value-at-a-given-index-in-a-bounded-array
1916-count-ways-to-build-rooms-in-an-ant-colony
2437-maximum-number-of-groups-entering-a-competition
3047-find-the-largest-area-of-square-inside-two-rectangles
3462-vowels-game-in-a-string
3625-count-number-of-trapezoids-ii
3627-maximum-median-sum-of-subsequences-of-size-3

Recursion

0010-regular-expression-matching
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0044-wildcard-matching
0060-permutation-sequence
0233-number-of-digit-one
1106-parsing-a-boolean-expression
1545-find-kth-bit-in-nth-binary-string

Depth-First Search

0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0130-surrounded-regions
0200-number-of-islands
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0329-longest-increasing-path-in-a-matrix
0332-reconstruct-itinerary
0341-flatten-nested-list-iterator
0385-mini-parser
0685-redundant-connection-ii
0770-couples-holding-hands
0803-cheapest-flights-within-k-stops
1161-maximum-level-sum-of-a-binary-tree
1428-jump-game-iii
1631-path-with-minimum-effort
1916-count-ways-to-build-rooms-in-an-ant-colony
3067-count-pairs-of-connectable-servers-in-a-weighted-tree-network
3729-unit-conversion-i

Breadth-First Search

0126-word-ladder-ii
0130-surrounded-regions
0200-number-of-islands
0301-remove-invalid-parentheses
0329-longest-increasing-path-in-a-matrix
0685-redundant-connection-ii
0770-couples-holding-hands
0803-cheapest-flights-within-k-stops
0877-shortest-path-visiting-all-nodes
1161-maximum-level-sum-of-a-binary-tree
1428-jump-game-iii
1631-path-with-minimum-effort
3729-unit-conversion-i

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions
0685-redundant-connection-ii
0770-couples-holding-hands
1627-graph-connectivity-with-threshold
1631-path-with-minimum-effort

Graph

0329-longest-increasing-path-in-a-matrix
0332-reconstruct-itinerary
0685-redundant-connection-ii
0770-couples-holding-hands
0803-cheapest-flights-within-k-stops
0877-shortest-path-visiting-all-nodes
1820-number-of-ways-to-reconstruct-a-tree
1891-count-pairs-of-nodes
1976-number-of-ways-to-arrive-at-destination
3729-unit-conversion-i

Tree

0096-unique-binary-search-trees
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0109-convert-sorted-list-to-binary-search-tree
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0341-flatten-nested-list-iterator
1161-maximum-level-sum-of-a-binary-tree
1820-number-of-ways-to-reconstruct-a-tree
1916-count-ways-to-build-rooms-in-an-ant-colony
2673-make-costs-of-paths-equal-in-a-binary-tree
3067-count-pairs-of-connectable-servers-in-a-weighted-tree-network

Bit Manipulation

0029-divide-two-integers
0137-single-number-ii
0201-bitwise-and-of-numbers-range
0260-single-number-iii
0287-find-the-duplicate-number
0798-transform-to-chessboard
0805-split-array-with-same-average
0828-chalkboard-xor-game
0877-shortest-path-visiting-all-nodes
0995-minimum-number-of-k-consecutive-bit-flips
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1461-check-if-a-string-contains-all-binary-codes-of-size-k
1930-unique-length-3-palindromic-subsequences
2035-partition-array-into-two-arrays-to-minimize-sum-difference
3611-construct-the-minimum-bitwise-array-ii

Brainteaser

0319-bulb-switcher
0828-chalkboard-xor-game
3462-vowels-game-in-a-string

Game Theory

0375-guess-number-higher-or-lower-ii
0828-chalkboard-xor-game
1406-stone-game-iii
3462-vowels-game-in-a-string
3627-maximum-median-sum-of-subsequences-of-size-3

Binary Tree

0096-unique-binary-search-trees
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0109-convert-sorted-list-to-binary-search-tree
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
1161-maximum-level-sum-of-a-binary-tree
2673-make-costs-of-paths-equal-in-a-binary-tree

Linked List

0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0082-remove-duplicates-from-sorted-list-ii
0109-convert-sorted-list-to-binary-search-tree
0114-flatten-binary-tree-to-linked-list
0146-lru-cache
0432-all-oone-data-structure
0528-swapping-nodes-in-a-linked-list
2389-design-a-text-editor

Divide and Conquer

0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0109-convert-sorted-list-to-binary-search-tree
0218-the-skyline-problem
0327-count-of-range-sum
3719-longest-balanced-subarray-i
3739-count-subarrays-with-majority-element-ii

Merge Sort

0023-merge-k-sorted-lists
0327-count-of-range-sum
3739-count-subarrays-with-majority-element-ii

Design

0146-lru-cache
0284-peeking-iterator
0341-flatten-nested-list-iterator
0381-insert-delete-getrandom-o1-duplicates-allowed
0432-all-oone-data-structure
0732-my-calendar-iii
0745-prefix-and-suffix-search
0885-exam-room
1622-fancy-sequence
2227-encrypt-and-decrypt-strings
2389-design-a-text-editor

Ordered Set

0218-the-skyline-problem
0220-contains-duplicate-iii
0327-count-of-range-sum
0699-falling-squares
0732-my-calendar-iii
0885-exam-room
2035-partition-array-into-two-arrays-to-minimize-sum-difference

Binary Search

0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0209-minimum-size-subarray-sum
0275-h-index-ii
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0327-count-of-range-sum
0354-russian-doll-envelopes
0410-split-array-largest-sum
0528-random-pick-with-weight
0540-single-element-in-a-sorted-array
0732-my-calendar-iii
1552-magnetic-force-between-two-balls
1631-path-with-minimum-effort
1793-maximum-score-of-a-good-subarray
1802-maximum-value-at-a-given-index-in-a-bounded-array
1891-count-pairs-of-nodes
2035-partition-array-into-two-arrays-to-minimize-sum-difference
2234-maximum-total-beauty-of-the-gardens
2437-maximum-number-of-groups-entering-a-competition
2673-maximize-win-from-two-segments
2779-maximum-beauty-of-an-array-after-applying-operation
3049-earliest-second-to-mark-indices-ii
3453-separate-squares-i

Counting

0229-majority-element-ii
0621-task-scheduler
1891-count-pairs-of-nodes
3713-longest-balanced-substring-i

Simulation

1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1545-find-kth-bit-in-nth-binary-string
2389-design-a-text-editor
2679-sum-in-a-matrix
3266-final-array-state-after-k-multiplication-operations-ii

Doubly-Linked List

0146-lru-cache
0432-all-oone-data-structure
2389-design-a-text-editor

Binary Indexed Tree

0218-the-skyline-problem
0327-count-of-range-sum

Segment Tree

0218-the-skyline-problem
0327-count-of-range-sum
0699-falling-squares
0732-my-calendar-iii
1622-fancy-sequence
3719-longest-balanced-subarray-i
3739-count-subarrays-with-majority-element-ii

Line Sweep

0218-the-skyline-problem

Bitmask

0805-split-array-with-same-average
0877-shortest-path-visiting-all-nodes
2035-partition-array-into-two-arrays-to-minimize-sum-difference

Topological Sort

0329-longest-increasing-path-in-a-matrix
1916-count-ways-to-build-rooms-in-an-ant-colony
1976-number-of-ways-to-arrive-at-destination

Memoization

0329-longest-increasing-path-in-a-matrix

Geometry

0149-max-points-on-a-line
3047-find-the-largest-area-of-square-inside-two-rectangles
3625-count-number-of-trapezoids-ii

Prefix Sum

0209-minimum-size-subarray-sum
0410-split-array-largest-sum
0528-random-pick-with-weight
0732-my-calendar-iii
0995-minimum-number-of-k-consecutive-bit-flips
1074-number-of-submatrices-that-sum-to-target
1524-number-of-sub-arrays-with-odd-sum
1895-largest-magic-square
1930-unique-length-3-palindromic-subsequences
2132-stamping-the-grid
2234-maximum-total-beauty-of-the-gardens
2488-count-subarrays-with-median-k
2906-construct-product-matrix
3070-count-submatrices-with-top-left-element-and-sum-less-than-k
3212-count-submatrices-with-equal-frequency-of-x-and-y
3546-equal-sum-grid-partition-i
3548-equal-sum-grid-partition-ii
3719-longest-balanced-subarray-i
3739-count-subarrays-with-majority-element-ii

Shortest Path

0803-cheapest-flights-within-k-stops
1976-number-of-ways-to-arrive-at-destination

Trie

0648-replace-words
0745-prefix-and-suffix-search
2227-encrypt-and-decrypt-strings

Eulerian Circuit

0332-reconstruct-itinerary

Enumeration

2234-maximum-total-beauty-of-the-gardens
3546-equal-sum-grid-partition-i
3548-equal-sum-grid-partition-ii
3713-longest-balanced-substring-i

String Matching

0686-repeated-string-match

Binary Search Tree

0096-unique-binary-search-trees
0109-convert-sorted-list-to-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree

Queue

0239-sliding-window-maximum
0341-flatten-nested-list-iterator
0995-minimum-number-of-k-consecutive-bit-flips

Monotonic Queue

0239-sliding-window-maximum

Randomized

0381-insert-delete-getrandom-o1-duplicates-allowed
0398-random-pick-index
0528-random-pick-with-weight

Number Theory

1627-graph-connectivity-with-threshold

Bucket Sort

0220-contains-duplicate-iii

Reservoir Sampling

0398-random-pick-index

Iterator

0284-peeking-iterator
0341-flatten-nested-list-iterator

Rolling Hash

1461-check-if-a-string-contains-all-binary-codes-of-size-k

Hash Function

1461-check-if-a-string-contains-all-binary-codes-of-size-k

Graph Theory

1916-count-ways-to-build-rooms-in-an-ant-colony

Combinatorics

1916-count-ways-to-build-rooms-in-an-ant-colony

Union-Find

0200-number-of-islands