LeetCode Topics

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

LeetCode Topics

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
0038-count-and-say
0049-group-anagrams
0067-add-binary
0076-minimum-window-substring
0139-word-break
0151-reverse-words-in-a-string
0208-implement-trie-prefix-tree
0297-serialize-and-deserialize-binary-tree
0392-is-subsequence
0424-longest-repeating-character-replacement
0451-sort-characters-by-frequency
0516-longest-palindromic-subsequence
0606-construct-string-from-binary-tree
0648-replace-words
0869-similar-string-groups
0944-delete-columns-to-make-sorted
0955-delete-columns-to-make-sorted-ii
1032-satisfiability-of-equality-equations
1129-longest-string-chain
1170-shortest-common-supersequence
1250-longest-common-subsequence
1252-break-a-palindrome
1264-maximum-number-of-words-you-can-type
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1351-replace-the-substring-for-balanced-string
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
1537-maximum-score-after-splitting-a-string
1578-minimum-time-to-make-rope-colorful
1636-number-of-substrings-with-only-1s
1781-check-if-two-string-arrays-are-equivalent
1818-maximum-score-from-removing-substrings
1915-check-if-one-string-swap-can-make-strings-equal
1930-unique-length-3-palindromic-subsequences
2113-find-the-kth-largest-integer-in-the-array
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2309-maximize-number-of-subsequences-in-a-string
2346-largest-3-same-digit-number-in-string
2395-longest-binary-subsequence-less-than-or-equal-to-k
2405-optimal-partition-of-string
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2470-removing-stars-from-a-string
2483-minimum-penalty-for-a-shop
2691-count-vowel-strings-in-ranges
2887-sort-vowels-in-a-string
3309-count-prefix-and-suffix-pairs-i
3337-count-substrings-starting-and-ending-with-given-character
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3462-vowels-game-in-a-string
3493-maximum-number-of-operations-to-move-ones-to-the-end
3606-coupon-code-validator
3617-find-the-original-typed-string-i
3753-maximum-difference-between-even-and-odd-frequency-i
3797-design-spreadsheet
3872-find-most-frequent-vowel-and-consonant

Prefix Sum


0209-minimum-size-subarray-sum
0303-range-sum-query-immutable
0560-subarray-sum-equals-k
1145-number-of-submatrices-that-sum-to-target
1535-build-array-where-you-can-find-the-maximum-exactly-k-comparisons
1537-maximum-score-after-splitting-a-string
1603-running-sum-of-1d-array
1930-unique-length-3-palindromic-subsequences
2309-maximize-number-of-subsequences-in-a-string
2334-number-of-flowers-in-full-bloom
2358-number-of-ways-to-split-array
2483-minimum-penalty-for-a-shop
2538-minimum-cost-to-make-array-equal
2691-count-vowel-strings-in-ranges
3096-minimum-levels-to-gain-more-points
3381-maximum-subarray-sum-with-length-divisible-by-k
3616-make-array-elements-equal-to-zero
3719-longest-balanced-subarray-i

Array


0001-two-sum
0014-longest-common-prefix
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array
0042-trapping-rain-water
0048-rotate-image
0049-group-anagrams
0051-n-queens
0054-spiral-matrix
0066-plus-one
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0139-word-break
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0213-house-robber-ii
0219-contains-duplicate-ii
0239-sliding-window-maximum
0268-missing-number
0300-longest-increasing-subsequence
0303-range-sum-query-immutable
0309-best-time-to-buy-and-sell-stock-with-cooldown
0324-wiggle-sort-ii
0368-largest-divisible-subset
0442-find-all-duplicates-in-an-array
0455-assign-cookies
0491-non-decreasing-subsequences
0496-next-greater-element-i
0498-diagonal-traverse
0502-ipo
0503-next-greater-element-ii
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence
0643-maximum-average-subarray-i
0646-maximum-length-of-pair-chain
0648-replace-words
0717-1-bit-and-2-bit-characters
0739-daily-temperatures
0759-set-intersection-size-at-least-two
0792-binary-search
0840-magic-squares-in-grid
0860-design-circular-queue
0869-similar-string-groups
0882-peak-index-in-a-mountain-array
0917-boats-to-save-people
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0944-delete-columns-to-make-sorted
0955-delete-columns-to-make-sorted-ii
0961-n-repeated-element-in-size-2n-array
0978-valid-mountain-array
0985-bag-of-tokens
1018-binary-prefix-divisible-by-5
1032-satisfiability-of-equality-equations
1036-rotting-oranges
1073-number-of-enclaves
1129-longest-string-chain
1145-number-of-submatrices-that-sum-to-target
1171-shortest-path-in-binary-matrix
1185-find-in-mountain-array
1200-minimum-absolute-difference
1253-sort-the-matrix-diagonally
1262-greatest-sum-divisible-by-three
1266-minimum-time-visiting-all-points
1293-three-consecutive-odds
1350-remove-sub-folders-from-the-filesystem
1352-maximum-profit-in-job-scheduling
1354-find-players-with-zero-or-one-losses
1407-group-the-people-given-the-group-size-they-belong-to
1421-find-numbers-with-even-number-of-digits
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1548-check-if-all-1s-are-at-least-length-k-places-away
1552-build-an-array-with-stack-operations
1578-minimum-time-to-make-rope-colorful
1603-running-sum-of-1d-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1646-kth-missing-positive-number
1656-count-good-triplets
1706-min-cost-to-connect-all-points
1753-path-with-minimum-effort
1781-check-if-two-string-arrays-are-equivalent
1813-maximum-erasure-value
1833-maximum-ice-cream-bars
1851-maximum-number-of-events-that-can-be-attended-ii
1876-map-of-highest-peak
1877-minimize-maximum-pair-sum-in-array
1878-check-if-array-is-sorted-and-rotated
1920-build-array-from-permutation
1927-maximum-ascending-subarray-sum
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2022-maximum-alternating-subsequence-sum
2038-nearest-exit-from-entrance-in-maze
2054-two-best-non-overlapping-events
2094-remove-stones-to-minimize-the-total
2101-last-day-where-you-can-still-cross
2110-number-of-smooth-descent-periods-of-a-stock
2113-find-the-kth-largest-integer-in-the-array
2136-earliest-possible-day-of-full-bloom
2164-two-best-non-overlapping-events
2169-simple-bank-system
2170-count-number-of-maximum-bitwise-or-subsets
2204-find-subsequence-of-length-k-with-the-largest-sum
2237-longest-palindrome-by-concatenating-two-letter-words
2244-minimum-rounds-to-complete-all-tasks
2274-keep-multiplying-found-values-by-two
2277-count-equal-and-divisible-pairs-in-an-array
2279-maximum-bags-with-full-capacity-of-rocks
2294-minimum-time-to-complete-trips
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2324-find-triangular-sum-of-an-array
2334-number-of-flowers-in-full-bloom
2343-count-unguarded-cells-in-the-grid
2358-number-of-ways-to-split-array
2387-partition-array-such-that-maximum-difference-is-k
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2497-maximum-matching-of-players-with-trainers
2503-longest-subarray-with-maximum-bitwise-and
2538-minimum-cost-to-make-array-equal
2614-maximum-count-of-positive-integer-and-negative-integer
2691-count-vowel-strings-in-ranges
2870-minimum-number-of-operations-to-make-array-empty
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3074-apple-redistribution-into-boxes
3096-minimum-levels-to-gain-more-points
3106-length-of-the-longest-subsequence-that-sums-to-target
3154-maximum-value-of-an-ordered-triplet-i
3184-maximum-balanced-subsequence-sum
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3242-count-elements-with-maximum-frequency
3251-maximum-area-of-longest-diagonal-rectangle
3309-count-prefix-and-suffix-pairs-i
3314-construct-the-minimum-bitwise-array-i
3315-construct-the-minimum-bitwise-array-ii
3321-type-of-triangle
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3381-maximum-subarray-sum-with-length-divisible-by-k
3429-special-array-i
3430-count-days-without-meetings
3454-minimum-operations-to-make-array-equal-to-target
3461-find-the-minimum-area-to-cover-all-ones-i
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i
3522-find-the-power-of-k-size-subarrays-i
3531-count-covered-buildings
3581-the-two-sneaky-numbers-of-digitville
3606-coupon-code-validator
3610-find-x-sum-of-all-k-long-subarrays-i
3612-adjacent-increasing-subarrays-detection-i
3616-make-array-elements-equal-to-zero
3619-adjacent-increasing-subarrays-detection-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3685-count-subarrays-of-length-three-with-a-condition
3719-longest-balanced-subarray-i
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3748-sort-matrix-by-diagonals
3788-maximum-unique-subarray-sum-after-deletion
3790-fruits-into-baskets-ii
3796-find-maximum-value-in-a-constrained-sequence
3797-design-spreadsheet
3824-minimum-k-to-reduce-array-within-limit
3825-longest-strictly-increasing-subsequence-with-non-zero-bitwise-and

Binary Search


0033-search-in-rotated-sorted-array
0069-sqrtx
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0268-missing-number
0300-longest-increasing-subsequence
0374-guess-number-higher-or-lower
0540-single-element-in-a-sorted-array
0792-binary-search
0882-peak-index-in-a-mountain-array
1185-find-in-mountain-array
1352-maximum-profit-in-job-scheduling
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1646-kth-missing-positive-number
1753-path-with-minimum-effort
1851-maximum-number-of-events-that-can-be-attended-ii
2054-two-best-non-overlapping-events
2101-last-day-where-you-can-still-cross
2164-two-best-non-overlapping-events
2294-minimum-time-to-complete-trips
2334-number-of-flowers-in-full-bloom
2538-minimum-cost-to-make-array-equal
2614-maximum-count-of-positive-integer-and-negative-integer
3184-maximum-balanced-subsequence-sum
3619-adjacent-increasing-subarrays-detection-ii
3790-fruits-into-baskets-ii
3824-minimum-k-to-reduce-array-within-limit
3825-longest-strictly-increasing-subsequence-with-non-zero-bitwise-and

Matrix


0048-rotate-image
0054-spiral-matrix
0074-search-a-2d-matrix
0200-number-of-islands
0498-diagonal-traverse
0840-magic-squares-in-grid
1036-rotting-oranges
1073-number-of-enclaves
1145-number-of-submatrices-that-sum-to-target
1171-shortest-path-in-binary-matrix
1253-sort-the-matrix-diagonally
1753-path-with-minimum-effort
1876-map-of-highest-peak
2038-nearest-exit-from-entrance-in-maze
2101-last-day-where-you-can-still-cross
2343-count-unguarded-cells-in-the-grid
3461-find-the-minimum-area-to-cover-all-ones-i
3748-sort-matrix-by-diagonals
3797-design-spreadsheet

Tree


0098-validate-binary-search-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0113-path-sum-ii
0199-binary-tree-right-side-view
0297-serialize-and-deserialize-binary-tree
0450-delete-node-in-a-bst
0501-find-mode-in-binary-search-tree
0606-construct-string-from-binary-tree
0764-n-ary-tree-level-order-traversal
0784-insert-into-a-binary-search-tree
0865-smallest-subtree-with-all-the-deepest-nodes
1123-lowest-common-ancestor-of-deepest-leaves
1339-maximum-product-of-splitted-binary-tree
1387-find-elements-in-a-contaminated-binary-tree
2493-reverse-odd-levels-of-binary-tree
3439-find-minimum-diameter-after-merging-two-trees

Depth-First Search


0098-validate-binary-search-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0113-path-sum-ii
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0297-serialize-and-deserialize-binary-tree
0501-find-mode-in-binary-search-tree
0547-number-of-provinces
0606-construct-string-from-binary-tree
0744-network-delay-time
0766-flatten-a-multilevel-doubly-linked-list
0801-is-graph-bipartite
0813-all-paths-from-source-to-target
0865-smallest-subtree-with-all-the-deepest-nodes
0869-similar-string-groups
0871-keys-and-rooms
0922-possible-bipartition
1073-number-of-enclaves
1123-lowest-common-ancestor-of-deepest-leaves
1339-maximum-product-of-splitted-binary-tree
1350-remove-sub-folders-from-the-filesystem
1387-find-elements-in-a-contaminated-binary-tree
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
2101-last-day-where-you-can-still-cross
2121-find-if-path-exists-in-graph
2201-valid-arrangement-of-pairs
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2438-find-closest-node-to-given-two-nodes
2493-reverse-odd-levels-of-binary-tree
2582-minimum-score-of-a-path-between-two-cities
3439-find-minimum-diameter-after-merging-two-trees

Breadth-First Search


0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0297-serialize-and-deserialize-binary-tree
0547-number-of-provinces
0744-network-delay-time
0764-n-ary-tree-level-order-traversal
0801-is-graph-bipartite
0813-all-paths-from-source-to-target
0865-smallest-subtree-with-all-the-deepest-nodes
0869-similar-string-groups
0871-keys-and-rooms
0922-possible-bipartition
1036-rotting-oranges
1073-number-of-enclaves
1123-lowest-common-ancestor-of-deepest-leaves
1171-shortest-path-in-binary-matrix
1387-find-elements-in-a-contaminated-binary-tree
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
1876-map-of-highest-peak
2038-nearest-exit-from-entrance-in-maze
2101-last-day-where-you-can-still-cross
2121-find-if-path-exists-in-graph
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2493-reverse-odd-levels-of-binary-tree
2582-minimum-score-of-a-path-between-two-cities
3439-find-minimum-diameter-after-merging-two-trees

Binary Tree


0098-validate-binary-search-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0113-path-sum-ii
0199-binary-tree-right-side-view
0297-serialize-and-deserialize-binary-tree
0450-delete-node-in-a-bst
0501-find-mode-in-binary-search-tree
0606-construct-string-from-binary-tree
0784-insert-into-a-binary-search-tree
0865-smallest-subtree-with-all-the-deepest-nodes
1123-lowest-common-ancestor-of-deepest-leaves
1339-maximum-product-of-splitted-binary-tree
1387-find-elements-in-a-contaminated-binary-tree
2493-reverse-odd-levels-of-binary-tree

Interactive


0374-guess-number-higher-or-lower
1185-find-in-mountain-array

Trie


0014-longest-common-prefix
0139-word-break
0208-implement-trie-prefix-tree
0648-replace-words
1350-remove-sub-folders-from-the-filesystem
3309-count-prefix-and-suffix-pairs-i

Rolling Hash


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

String Matching


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

Hash Function


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

Greedy


0122-best-time-to-buy-and-sell-stock-ii
0324-wiggle-sort-ii
0455-assign-cookies
0502-ipo
0646-maximum-length-of-pair-chain
0759-set-intersection-size-at-least-two
0917-boats-to-save-people
0955-delete-columns-to-make-sorted-ii
0985-bag-of-tokens
1033-broken-calculator
1252-break-a-palindrome
1262-greatest-sum-divisible-by-three
1407-group-the-people-given-the-group-size-they-belong-to
1448-maximum-69-number
1478-maximum-number-of-events-that-can-be-attended
1578-minimum-time-to-make-rope-colorful
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1818-maximum-score-from-removing-substrings
1833-maximum-ice-cream-bars
1877-minimize-maximum-pair-sum-in-array
2094-remove-stones-to-minimize-the-total
2136-earliest-possible-day-of-full-bloom
2237-longest-palindrome-by-concatenating-two-letter-words
2244-minimum-rounds-to-complete-all-tasks
2279-maximum-bags-with-full-capacity-of-rocks
2309-maximize-number-of-subsequences-in-a-string
2387-partition-array-such-that-maximum-difference-is-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2405-optimal-partition-of-string
2497-maximum-matching-of-players-with-trainers
2538-minimum-cost-to-make-array-equal
2704-maximum-difference-by-remapping-a-digit
2870-minimum-number-of-operations-to-make-array-empty
3074-apple-redistribution-into-boxes
3445-lexicographically-minimum-string-after-removing-stars
3454-minimum-operations-to-make-array-equal-to-target
3493-maximum-number-of-operations-to-move-ones-to-the-end
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3788-maximum-unique-subarray-sum-after-deletion
3796-find-maximum-value-in-a-constrained-sequence

Sorting


0015-3sum
0018-4sum
0049-group-anagrams
0075-sort-colors
0147-insertion-sort-list
0268-missing-number
0324-wiggle-sort-ii
0368-largest-divisible-subset
0451-sort-characters-by-frequency
0455-assign-cookies
0502-ipo
0594-longest-harmonious-subsequence
0646-maximum-length-of-pair-chain
0759-set-intersection-size-at-least-two
0917-boats-to-save-people
0985-bag-of-tokens
1129-longest-string-chain
1200-minimum-absolute-difference
1253-sort-the-matrix-diagonally
1262-greatest-sum-divisible-by-three
1352-maximum-profit-in-job-scheduling
1354-find-players-with-zero-or-one-losses
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1833-maximum-ice-cream-bars
1851-maximum-number-of-events-that-can-be-attended-ii
1877-minimize-maximum-pair-sum-in-array
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2054-two-best-non-overlapping-events
2113-find-the-kth-largest-integer-in-the-array
2136-earliest-possible-day-of-full-bloom
2164-two-best-non-overlapping-events
2204-find-subsequence-of-length-k-with-the-largest-sum
2274-keep-multiplying-found-values-by-two
2279-maximum-bags-with-full-capacity-of-rocks
2334-number-of-flowers-in-full-bloom
2387-partition-array-such-that-maximum-difference-is-k
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2497-maximum-matching-of-players-with-trainers
2538-minimum-cost-to-make-array-equal
2887-sort-vowels-in-a-string
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3074-apple-redistribution-into-boxes
3321-type-of-triangle
3430-count-days-without-meetings
3531-count-covered-buildings
3606-coupon-code-validator
3748-sort-matrix-by-diagonals

Hash Table


0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0049-group-anagrams
0076-minimum-window-substring
0139-word-break
0208-implement-trie-prefix-tree
0219-contains-duplicate-ii
0268-missing-number
0424-longest-repeating-character-replacement
0442-find-all-duplicates-in-an-array
0451-sort-characters-by-frequency
0491-non-decreasing-subsequences
0496-next-greater-element-i
0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence
0648-replace-words
0840-magic-squares-in-grid
0865-smallest-subtree-with-all-the-deepest-nodes
0869-similar-string-groups
0940-fruit-into-baskets
0961-n-repeated-element-in-size-2n-array
1015-smallest-integer-divisible-by-k
1123-lowest-common-ancestor-of-deepest-leaves
1129-longest-string-chain
1145-number-of-submatrices-that-sum-to-target
1264-maximum-number-of-words-you-can-type
1354-find-players-with-zero-or-one-losses
1387-find-elements-in-a-contaminated-binary-tree
1407-group-the-people-given-the-group-size-they-belong-to
1500-count-largest-group
1510-find-lucky-integer-in-an-array
1813-maximum-erasure-value
1915-check-if-one-string-swap-can-make-strings-equal
1930-unique-length-3-palindromic-subsequences
2169-simple-bank-system
2204-find-subsequence-of-length-k-with-the-largest-sum
2237-longest-palindrome-by-concatenating-two-letter-words
2244-minimum-rounds-to-complete-all-tasks
2274-keep-multiplying-found-values-by-two
2308-divide-array-into-equal-pairs
2334-number-of-flowers-in-full-bloom
2405-optimal-partition-of-string
2455-node-with-highest-edge-score
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2870-minimum-number-of-operations-to-make-array-empty
3242-count-elements-with-maximum-frequency
3381-maximum-subarray-sum-with-length-divisible-by-k
3445-lexicographically-minimum-string-after-removing-stars
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i
3531-count-covered-buildings
3581-the-two-sneaky-numbers-of-digitville
3606-coupon-code-validator
3610-find-x-sum-of-all-k-long-subarrays-i
3621-minimum-operations-to-make-array-values-equal-to-k
3719-longest-balanced-subarray-i
3753-maximum-difference-between-even-and-odd-frequency-i
3788-maximum-unique-subarray-sum-after-deletion
3797-design-spreadsheet
3872-find-most-frequent-vowel-and-consonant

Ordered Set


2334-number-of-flowers-in-full-bloom
3507-minimum-pair-removal-to-sort-array-i
3790-fruits-into-baskets-ii

Union Find


0200-number-of-islands
0547-number-of-provinces
0801-is-graph-bipartite
0869-similar-string-groups
0922-possible-bipartition
1032-satisfiability-of-equality-equations
1073-number-of-enclaves
1442-number-of-operations-to-make-network-connected
1706-min-cost-to-connect-all-points
1753-path-with-minimum-effort
2101-last-day-where-you-can-still-cross
2121-find-if-path-exists-in-graph
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2582-minimum-score-of-a-path-between-two-cities

Heap (Priority Queue)


0239-sliding-window-maximum
0451-sort-characters-by-frequency
0502-ipo
0744-network-delay-time
1478-maximum-number-of-events-that-can-be-attended
1753-path-with-minimum-effort
2054-two-best-non-overlapping-events
2094-remove-stones-to-minimize-the-total
2113-find-the-kth-largest-integer-in-the-array
2164-two-best-non-overlapping-events
2204-find-subsequence-of-length-k-with-the-largest-sum
2473-max-sum-of-a-pair-with-equal-sum-of-digits
3445-lexicographically-minimum-string-after-removing-stars
3507-minimum-pair-removal-to-sort-array-i
3610-find-x-sum-of-all-k-long-subarrays-i

Math


0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0189-rotate-array
0268-missing-number
0319-bulb-switcher
0326-power-of-three
0342-power-of-four
0368-largest-divisible-subset
0840-magic-squares-in-grid
1015-smallest-integer-divisible-by-k
1033-broken-calculator
1236-n-th-tribonacci-number
1266-minimum-time-visiting-all-points
1279-prime-arrangements
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1448-maximum-69-number
1500-count-largest-group
1636-number-of-substrings-with-only-1s
2050-count-good-numbers
2110-number-of-smooth-descent-periods-of-a-stock
2288-count-operations-to-obtain-zero
2324-find-triangular-sum-of-an-array
2481-strictly-palindromic-number
2704-maximum-difference-by-remapping-a-digit
3172-divisible-and-non-divisible-sums-difference
3190-find-minimum-operations-to-make-all-elements-divisible-by-three
3279-alice-and-bob-playing-flower-game
3321-type-of-triangle
3337-count-substrings-starting-and-ending-with-given-character
3462-vowels-game-in-a-string
3568-find-the-key-of-the-numbers
3581-the-two-sneaky-numbers-of-digitville
3600-find-the-k-th-character-in-string-game-i
3676-smallest-number-with-all-set-bits
3830-find-closest-person

Simulation


0054-spiral-matrix
0067-add-binary
0498-diagonal-traverse
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1552-build-an-array-with-stack-operations
1920-build-array-from-permutation
2169-simple-bank-system
2260-divide-a-string-into-groups-of-size-k
2274-keep-multiplying-found-values-by-two
2288-count-operations-to-obtain-zero
2299-merge-nodes-in-between-zeros
2324-find-triangular-sum-of-an-array
2343-count-unguarded-cells-in-the-grid
2470-removing-stars-from-a-string
3447-clear-digits
3507-minimum-pair-removal-to-sort-array-i
3600-find-the-k-th-character-in-string-game-i
3616-make-array-elements-equal-to-zero
3790-fruits-into-baskets-ii

Binary Search Tree


0098-validate-binary-search-tree
0450-delete-node-in-a-bst
0501-find-mode-in-binary-search-tree
0784-insert-into-a-binary-search-tree

Linked List


0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0147-insertion-sort-list
0237-delete-node-in-a-linked-list
0766-flatten-a-multilevel-doubly-linked-list
0860-design-circular-queue
1411-convert-binary-number-in-a-linked-list-to-integer
2299-merge-nodes-in-between-zeros
2573-remove-nodes-from-linked-list
3501-delete-nodes-from-linked-list-present-in-array
3507-minimum-pair-removal-to-sort-array-i

Two Pointers


0005-longest-palindromic-substring
0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0042-trapping-rain-water
0075-sort-colors
0082-remove-duplicates-from-sorted-list-ii
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0392-is-subsequence
0455-assign-cookies
0917-boats-to-save-people
0985-bag-of-tokens
1129-longest-string-chain
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1877-minimize-maximum-pair-sum-in-array
2320-find-all-k-distant-indices-in-an-array
2481-strictly-palindromic-number
2497-maximum-matching-of-players-with-trainers

Stack


0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0232-implement-queue-using-stacks
0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
1552-build-an-array-with-stack-operations
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1818-maximum-score-from-removing-substrings
2470-removing-stars-from-a-string
2573-remove-nodes-from-linked-list
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3454-minimum-operations-to-make-array-equal-to-target

Design


0208-implement-trie-prefix-tree
0232-implement-queue-using-stacks
0297-serialize-and-deserialize-binary-tree
0303-range-sum-query-immutable
0860-design-circular-queue
1387-find-elements-in-a-contaminated-binary-tree
2169-simple-bank-system
3797-design-spreadsheet

Queue


0232-implement-queue-using-stacks
0239-sliding-window-maximum
0860-design-circular-queue

Graph


0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0744-network-delay-time
0801-is-graph-bipartite
0813-all-paths-from-source-to-target
0871-keys-and-rooms
0922-possible-bipartition
1032-satisfiability-of-equality-equations
1442-number-of-operations-to-make-network-connected
1661-minimum-number-of-vertices-to-reach-all-nodes
1706-min-cost-to-connect-all-points
2121-find-if-path-exists-in-graph
2201-valid-arrangement-of-pairs
2403-count-unreachable-pairs-of-nodes-in-an-undirected-graph
2438-find-closest-node-to-given-two-nodes
2455-node-with-highest-edge-score
2582-minimum-score-of-a-path-between-two-cities
3439-find-minimum-diameter-after-merging-two-trees

Topological Sort


0207-course-schedule
0210-course-schedule-ii

Counting


0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
1354-find-players-with-zero-or-one-losses
1510-find-lucky-integer-in-an-array
1915-check-if-one-string-swap-can-make-strings-equal
2237-longest-palindrome-by-concatenating-two-letter-words
2244-minimum-rounds-to-complete-all-tasks
2308-divide-array-into-equal-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
2870-minimum-number-of-operations-to-make-array-empty
3242-count-elements-with-maximum-frequency
3337-count-substrings-starting-and-ending-with-given-character
3493-maximum-number-of-operations-to-move-ones-to-the-end
3753-maximum-difference-between-even-and-odd-frequency-i
3872-find-most-frequent-vowel-and-consonant

Shortest Path


0744-network-delay-time

Minimum Spanning Tree


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

Sliding Window


0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0594-longest-harmonious-subsequence
0643-maximum-average-subarray-i
0940-fruit-into-baskets
1351-replace-the-substring-for-balanced-string
1813-maximum-erasure-value
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2463-minimum-recolors-to-get-k-consecutive-black-blocks
3522-find-the-power-of-k-size-subarrays-i
3610-find-x-sum-of-all-k-long-subarrays-i
3743-reschedule-meetings-for-maximum-free-time-i

Bucket Sort


0451-sort-characters-by-frequency

Brainteaser


0319-bulb-switcher
2481-strictly-palindromic-number
2503-longest-subarray-with-maximum-bitwise-and
3462-vowels-game-in-a-string

Backtracking


0051-n-queens
0078-subsets
0113-path-sum-ii
0491-non-decreasing-subsequences
0813-all-paths-from-source-to-target
1415-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
2170-count-number-of-maximum-bitwise-or-subsets

Segment Tree


3184-maximum-balanced-subsequence-sum
3719-longest-balanced-subarray-i
3790-fruits-into-baskets-ii

Eulerian Circuit


2201-valid-arrangement-of-pairs

Dynamic Programming


0005-longest-palindromic-substring
0042-trapping-rain-water
0070-climbing-stairs
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0139-word-break
0198-house-robber
0213-house-robber-ii
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0368-largest-divisible-subset
0392-is-subsequence
0516-longest-palindromic-subsequence
0646-maximum-length-of-pair-chain
0934-bitwise-ors-of-subarrays
1129-longest-string-chain
1170-shortest-common-supersequence
1236-n-th-tribonacci-number
1250-longest-common-subsequence
1262-greatest-sum-divisible-by-three
1352-maximum-profit-in-job-scheduling
1535-build-array-where-you-can-find-the-maximum-exactly-k-comparisons
1578-minimum-time-to-make-rope-colorful
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1851-maximum-number-of-events-that-can-be-attended-ii
2022-maximum-alternating-subsequence-sum
2028-the-earliest-and-latest-rounds-where-players-compete
2054-two-best-non-overlapping-events
2110-number-of-smooth-descent-periods-of-a-stock
2164-two-best-non-overlapping-events
2395-longest-binary-subsequence-less-than-or-equal-to-k
3106-length-of-the-longest-subsequence-that-sums-to-target
3184-maximum-balanced-subsequence-sum
3454-minimum-operations-to-make-array-equal-to-target
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii

Memoization


0070-climbing-stairs
0139-word-break
1236-n-th-tribonacci-number
2028-the-earliest-and-latest-rounds-where-players-compete
2395-longest-binary-subsequence-less-than-or-equal-to-k

Bit Manipulation


0067-add-binary
0078-subsets
0268-missing-number
0342-power-of-four
0491-non-decreasing-subsequences
0868-binary-gap
0934-bitwise-ors-of-subarrays
1009-complement-of-base-10-integer
1018-binary-prefix-divisible-by-5
1404-number-of-steps-to-reduce-a-number-in-binary-representation-to-one
1930-unique-length-3-palindromic-subsequences
2170-count-number-of-maximum-bitwise-or-subsets
2308-divide-array-into-equal-pairs
2503-longest-subarray-with-maximum-bitwise-and
3314-construct-the-minimum-bitwise-array-i
3315-construct-the-minimum-bitwise-array-ii
3600-find-the-k-th-character-in-string-game-i
3676-smallest-number-with-all-set-bits
3825-longest-strictly-increasing-subsequence-with-non-zero-bitwise-and

Recursion


0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0050-powx-n
0326-power-of-three
0342-power-of-four
2050-count-good-numbers
2573-remove-nodes-from-linked-list
3600-find-the-k-th-character-in-string-game-i

Enumeration


1656-count-good-triplets
2170-count-number-of-maximum-bitwise-or-subsets
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3741-reschedule-meetings-for-maximum-free-time-ii
3825-longest-strictly-increasing-subsequence-with-non-zero-bitwise-and

Doubly-Linked List


0766-flatten-a-multilevel-doubly-linked-list
3507-minimum-pair-removal-to-sort-array-i

Binary Indexed Tree


3184-maximum-balanced-subsequence-sum

Divide and Conquer


0324-wiggle-sort-ii
2113-find-the-kth-largest-integer-in-the-array
3719-longest-balanced-subarray-i

Quickselect


0324-wiggle-sort-ii
2113-find-the-kth-largest-integer-in-the-array

Monotonic Stack


0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
2573-remove-nodes-from-linked-list
3454-minimum-operations-to-make-array-equal-to-target

Game Theory


3462-vowels-game-in-a-string

Monotonic Queue


0239-sliding-window-maximum

Combinatorics


2324-find-triangular-sum-of-an-array

Counting Sort


1833-maximum-ice-cream-bars

Geometry


1266-minimum-time-visiting-all-points

Name		Name	Last commit message	Last commit date
Latest commit History 1,837 Commits
0001-two-sum		0001-two-sum
0003-longest-substring-without-repeating-characters		0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring		0005-longest-palindromic-substring
0009-palindrome-number		0009-palindrome-number
0012-integer-to-roman		0012-integer-to-roman
0013-roman-to-integer		0013-roman-to-integer
0014-longest-common-prefix		0014-longest-common-prefix
0015-3sum		0015-3sum
0018-4sum		0018-4sum
0019-remove-nth-node-from-end-of-list		0019-remove-nth-node-from-end-of-list
0020-valid-parentheses		0020-valid-parentheses
0021-merge-two-sorted-lists		0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs		0024-swap-nodes-in-pairs
0026-remove-duplicates-from-sorted-array		0026-remove-duplicates-from-sorted-array
0033-search-in-rotated-sorted-array		0033-search-in-rotated-sorted-array
0038-count-and-say		0038-count-and-say
0042-trapping-rain-water		0042-trapping-rain-water
0048-rotate-image		0048-rotate-image
0049-group-anagrams		0049-group-anagrams
0050-powx-n		0050-powx-n
0051-n-queens		0051-n-queens
0054-spiral-matrix		0054-spiral-matrix
0066-plus-one		0066-plus-one
0067-add-binary		0067-add-binary
0069-sqrtx		0069-sqrtx
0070-climbing-stairs		0070-climbing-stairs
0074-search-a-2d-matrix		0074-search-a-2d-matrix
0075-sort-colors		0075-sort-colors
0076-minimum-window-substring		0076-minimum-window-substring
0078-subsets		0078-subsets
0081-search-in-rotated-sorted-array-ii		0081-search-in-rotated-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii		0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list		0083-remove-duplicates-from-sorted-list
0084-largest-rectangle-in-histogram		0084-largest-rectangle-in-histogram
0092-reverse-linked-list-ii		0092-reverse-linked-list-ii
0098-validate-binary-search-tree		0098-validate-binary-search-tree
0101-symmetric-tree		0101-symmetric-tree
0104-maximum-depth-of-binary-tree		0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree		0110-balanced-binary-tree
0113-path-sum-ii		0113-path-sum-ii
0118-pascals-triangle		0118-pascals-triangle
0119-pascals-triangle-ii		0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock		0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii		0122-best-time-to-buy-and-sell-stock-ii
0139-word-break		0139-word-break
0147-insertion-sort-list		0147-insertion-sort-list
0151-reverse-words-in-a-string		0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted		0167-two-sum-ii-input-array-is-sorted
0189-rotate-array		0189-rotate-array
0198-house-robber		0198-house-robber
0199-binary-tree-right-side-view		0199-binary-tree-right-side-view
0200-number-of-islands		0200-number-of-islands
0207-course-schedule		0207-course-schedule
0208-implement-trie-prefix-tree		0208-implement-trie-prefix-tree
0209-minimum-size-subarray-sum		0209-minimum-size-subarray-sum
0210-course-schedule-ii		0210-course-schedule-ii
0213-house-robber-ii		0213-house-robber-ii
0219-contains-duplicate-ii		0219-contains-duplicate-ii
0232-implement-queue-using-stacks		0232-implement-queue-using-stacks
0237-delete-node-in-a-linked-list		0237-delete-node-in-a-linked-list
0239-sliding-window-maximum		0239-sliding-window-maximum
0268-missing-number		0268-missing-number
0297-serialize-and-deserialize-binary-tree		0297-serialize-and-deserialize-binary-tree
0300-longest-increasing-subsequence		0300-longest-increasing-subsequence
0303-range-sum-query-immutable		0303-range-sum-query-immutable
0309-best-time-to-buy-and-sell-stock-with-cooldown		0309-best-time-to-buy-and-sell-stock-with-cooldown
0319-bulb-switcher		0319-bulb-switcher
0324-wiggle-sort-ii		0324-wiggle-sort-ii
0326-power-of-three		0326-power-of-three
0342-power-of-four		0342-power-of-four
0368-largest-divisible-subset		0368-largest-divisible-subset
0374-guess-number-higher-or-lower		0374-guess-number-higher-or-lower
0392-is-subsequence		0392-is-subsequence
0424-longest-repeating-character-replacement		0424-longest-repeating-character-replacement
0442-find-all-duplicates-in-an-array		0442-find-all-duplicates-in-an-array
0450-delete-node-in-a-bst		0450-delete-node-in-a-bst
0451-sort-characters-by-frequency		0451-sort-characters-by-frequency
0455-assign-cookies		0455-assign-cookies
0491-non-decreasing-subsequences		0491-non-decreasing-subsequences
0496-next-greater-element-i		0496-next-greater-element-i
0498-diagonal-traverse		0498-diagonal-traverse
0501-find-mode-in-binary-search-tree		0501-find-mode-in-binary-search-tree
0502-ipo		0502-ipo
0503-next-greater-element-ii		0503-next-greater-element-ii
0516-longest-palindromic-subsequence		0516-longest-palindromic-subsequence
0540-single-element-in-a-sorted-array		0540-single-element-in-a-sorted-array
0547-number-of-provinces		0547-number-of-provinces
0560-subarray-sum-equals-k		0560-subarray-sum-equals-k
0594-longest-harmonious-subsequence		0594-longest-harmonious-subsequence
0606-construct-string-from-binary-tree		0606-construct-string-from-binary-tree
0643-maximum-average-subarray-i		0643-maximum-average-subarray-i
0646-maximum-length-of-pair-chain		0646-maximum-length-of-pair-chain
0648-replace-words		0648-replace-words
0717-1-bit-and-2-bit-characters		0717-1-bit-and-2-bit-characters
0739-daily-temperatures		0739-daily-temperatures
0744-network-delay-time		0744-network-delay-time
0759-set-intersection-size-at-least-two		0759-set-intersection-size-at-least-two
0764-n-ary-tree-level-order-traversal		0764-n-ary-tree-level-order-traversal
0766-flatten-a-multilevel-doubly-linked-list		0766-flatten-a-multilevel-doubly-linked-list
0784-insert-into-a-binary-search-tree		0784-insert-into-a-binary-search-tree

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