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

LeetCode Topics

Two Pointers

0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0042-trapping-rain-water
0075-sort-colors
0141-linked-list-cycle
0142-linked-list-cycle-ii
0295-find-median-from-data-stream
0455-assign-cookies
0633-sum-of-square-numbers
0868-push-dominoes
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2320-find-all-k-distant-indices-in-an-array
2497-maximum-matching-of-players-with-trainers
2588-maximum-number-of-points-from-grid-queries
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3683-find-the-lexicographically-largest-string-from-the-box-i
3959-maximum-total-from-optimal-activation-order
3973-flip-square-submatrix-vertically

String

0038-count-and-say
0058-length-of-last-word
0076-minimum-window-substring
0126-word-ladder-ii
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0399-evaluate-division
0516-longest-palindromic-subsequence
0730-count-different-palindromic-subsequences
0746-prefix-and-suffix-search
0868-push-dominoes
1058-lexicographically-smallest-equivalent-string
1093-recover-a-tree-from-preorder-traversal
1160-letter-tile-possibilities
1170-shortest-common-supersequence
1250-longest-common-subsequence
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1403-palindrome-partitioning-iii
1460-number-of-substrings-containing-all-three-characters
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1818-maximum-score-from-removing-substrings
1915-check-if-one-string-swap-can-make-strings-equal
2021-remove-all-occurrences-of-a-substring
2079-delete-duplicate-folders-in-system
2107-find-unique-binary-string
2140-longest-subsequence-repeated-k-times
2221-check-if-a-parentheses-string-can-be-valid
2237-longest-palindrome-by-concatenating-two-letter-words
2256-count-words-obtained-after-adding-a-letter
2260-divide-a-string-into-groups-of-size-k
2292-counting-words-with-a-given-prefix
2395-longest-binary-subsequence-less-than-or-equal-to-k
2456-construct-smallest-number-from-di-string
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2510-maximum-deletions-on-a-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2577-count-palindromic-subsequences
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3194-find-words-containing-character
3243-count-the-number-of-powerful-integers
3360-minimum-deletions-to-make-string-k-special
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3617-find-the-original-typed-string-i
3618-find-the-original-typed-string-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3683-find-the-lexicographically-largest-string-from-the-box-i
3707-find-the-most-common-response
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3761-maximum-difference-between-even-and-odd-frequency-ii
3771-select-k-disjoint-special-substrings

String Matching

1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
2510-maximum-deletions-on-a-string

Array

0001-two-sum
0015-3sum
0018-4sum
0042-trapping-rain-water
0046-permutations
0073-set-matrix-zeroes
0075-sort-colors
0084-largest-rectangle-in-histogram
0118-pascals-triangle
0135-candy
0149-max-points-on-a-line
0213-house-robber-ii
0218-the-skyline-problem
0238-product-of-array-except-self
0239-sliding-window-maximum
0347-top-k-frequent-elements
0368-largest-divisible-subset
0399-evaluate-division
0407-trapping-rain-water-ii
0416-partition-equal-subset-sum
0421-maximum-xor-of-two-numbers-in-an-array
0455-assign-cookies
0554-brick-wall
0594-longest-harmonious-subsequence
0632-smallest-range-covering-elements-from-k-lists
0746-prefix-and-suffix-search
0797-rabbits-in-forest
0823-split-array-with-same-average
0854-making-a-large-island
0876-hand-of-straights
0881-loud-and-rich
0905-length-of-longest-fibonacci-subsequence
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0945-snakes-and-ladders
0954-maximum-sum-circular-subarray
0982-minimum-increment-to-make-array-unique
1049-minimum-domino-rotations-for-equal-row
1050-construct-binary-search-tree-from-preorder-traversal
1227-number-of-equivalent-domino-pairs
1293-three-consecutive-odds
1335-maximum-candies-allocated-to-k-children
1348-maximum-score-of-spliced-array
1350-remove-sub-folders-from-the-filesystem
1364-tuple-with-same-product
1396-count-servers-that-communicate
1421-find-numbers-with-even-number-of-digits
1424-maximum-candies-you-can-get-from-boxes
1477-product-of-the-last-k-numbers
1478-maximum-number-of-events-that-can-be-attended
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1510-find-lucky-integer-in-an-array
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1631-number-of-sub-arrays-with-odd-sum
1656-count-good-triplets
1669-minimum-cost-to-cut-a-stick
1753-path-with-minimum-effort
1813-maximum-erasure-value
1819-construct-the-lexicographically-largest-valid-sequence
1826-maximum-xor-with-an-element-from-array
1849-maximum-absolute-sum-of-any-subarray
1851-maximum-number-of-events-that-can-be-attended-ii
1876-map-of-highest-peak
1878-check-if-array-is-sorted-and-rotated
1886-minimum-limit-of-balls-in-a-bag
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2048-build-array-from-permutation
2068-maximum-genetic-difference-query
2079-delete-duplicate-folders-in-system
2107-find-unique-binary-string
2144-maximum-difference-between-increasing-elements
2145-grid-game
2150-kth-smallest-product-of-two-sorted-arrays
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2249-count-the-hidden-sequences
2256-count-words-obtained-after-adding-a-letter
2262-solving-questions-with-brainpower
2263-maximum-running-time-of-n-computers
2267-minimum-difference-in-sums-after-removal-of-elements
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2292-counting-words-with-a-given-prefix
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2344-escape-the-spreading-fire
2387-partition-array-such-that-maximum-difference-is-k
2394-count-subarrays-with-score-less-than-k
2400-minimum-score-after-removals-on-a-tree
2432-number-of-zero-filled-subarrays
2448-count-number-of-bad-pairs
2449-maximum-number-of-robots-within-budget
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2478-longest-nice-subarray
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2498-smallest-subarrays-with-maximum-bitwise-or
2505-number-of-good-paths
2527-count-subarrays-with-fixed-bounds
2533-bitwise-xor-of-all-pairings
2564-most-profitable-path-in-a-tree
2588-maximum-number-of-points-from-grid-queries
2601-number-of-great-partitions
2614-maximum-count-of-positive-integer-and-negative-integer
2626-count-the-number-of-good-subarrays
2681-put-marbles-in-bags
2685-first-completely-painted-row-or-column
2690-house-robber-iv
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
2720-minimize-the-maximum-difference-of-pairs
2739-minimize-the-total-price-of-the-trips
2764-maximum-number-of-fish-in-a-grid
2766-find-the-prefix-common-array-of-two-arrays
2856-count-complete-subarrays-in-an-array
2914-find-the-safest-path-in-a-grid
2915-count-of-interesting-subarrays
3001-apply-operations-to-maximize-score
3079-minimum-edge-weight-equilibrium-queries-in-a-tree
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3154-maximum-value-of-an-ordered-triplet-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3194-find-words-containing-character
3197-maximum-strong-pair-xor-ii
3213-count-subarrays-where-max-element-appears-at-least-k-times
3219-make-lexicographically-smallest-array-by-swapping-elements
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3348-minimum-cost-walk-in-weighted-graph
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3429-special-array-i
3430-count-days-without-meetings
3434-find-the-number-of-distinct-colors-among-the-balls
3483-alternating-groups-ii
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3616-make-array-elements-equal-to-zero
3621-minimum-operations-to-make-array-values-equal-to-k
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3648-find-the-maximum-number-of-fruits-collected
3649-minimum-time-to-break-locks-i
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3685-count-subarrays-of-length-three-with-a-condition
3686-count-beautiful-splits-in-an-array
3697-minimum-increments-for-target-multiples-in-an-array
3707-find-the-most-common-response
3743-reschedule-meetings-for-maximum-free-time-i
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3776-find-minimum-cost-to-remove-array-elements
3788-maximum-unique-subarray-sum-after-deletion
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3819-count-covered-buildings
3822-fill-a-special-grid
3833-merge-operations-for-minimum-travel-time
3838-path-existence-queries-in-a-graph-i
3841-concatenated-divisibility
3850-equal-sum-grid-partition-ii
3851-find-sum-of-array-product-of-magical-sequences
3852-path-existence-queries-in-a-graph-ii
3858-subtree-inversion-sum
3882-partition-array-for-maximum-xor-and-and
3896-minimum-time-to-transport-all-individuals
3900-find-weighted-median-node-in-tree
3959-maximum-total-from-optimal-activation-order
3973-flip-square-submatrix-vertically
3974-xor-after-range-multiplication-queries-i
3975-xor-after-range-multiplication-queries-ii
3980-best-time-to-buy-and-sell-stock-using-strategy

Binary Search

0633-sum-of-square-numbers
1335-maximum-candies-allocated-to-k-children
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1753-path-with-minimum-effort
1851-maximum-number-of-events-that-can-be-attended-ii
1886-minimum-limit-of-balls-in-a-bag
2150-kth-smallest-product-of-two-sorted-arrays
2180-maximum-number-of-tasks-you-can-assign
2263-maximum-running-time-of-n-computers
2280-count-good-triplets-in-an-array
2344-escape-the-spreading-fire
2394-count-subarrays-with-score-less-than-k
2449-maximum-number-of-robots-within-budget
2498-smallest-subarrays-with-maximum-bitwise-or
2614-maximum-count-of-positive-integer-and-negative-integer
2690-house-robber-iv
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
2914-find-the-safest-path-in-a-grid
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3838-path-existence-queries-in-a-graph-i
3852-path-existence-queries-in-a-graph-ii
3900-find-weighted-median-node-in-tree

Simulation

2021-remove-all-occurrences-of-a-substring
2048-build-array-from-permutation
2260-divide-a-string-into-groups-of-size-k
2479-meeting-rooms-iii
2695-find-score-of-an-array-after-marking-all-elements
3434-find-the-number-of-distinct-colors-among-the-balls
3447-clear-digits
3600-find-the-k-th-character-in-string-game-i
3616-make-array-elements-equal-to-zero
3790-fruits-into-baskets-ii
3974-xor-after-range-multiplication-queries-i

Prefix Sum

0238-product-of-array-except-self
1477-product-of-the-last-k-numbers
1631-number-of-sub-arrays-with-odd-sum
2145-grid-game
2249-count-the-hidden-sequences
2394-count-subarrays-with-score-less-than-k
2449-maximum-number-of-robots-within-budget
2915-count-of-interesting-subarrays
3616-make-array-elements-equal-to-zero
3618-find-the-original-typed-string-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair
3833-merge-operations-for-minimum-travel-time
3850-equal-sum-grid-partition-ii
3980-best-time-to-buy-and-sell-stock-using-strategy

Hash Table

0001-two-sum
0073-set-matrix-zeroes
0076-minimum-window-substring
0126-word-ladder-ii
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0149-max-points-on-a-line
0208-implement-trie-prefix-tree
0347-top-k-frequent-elements
0421-maximum-xor-of-two-numbers-in-an-array
0460-lfu-cache
0554-brick-wall
0594-longest-harmonious-subsequence
0632-smallest-range-covering-elements-from-k-lists
0746-prefix-and-suffix-search
0797-rabbits-in-forest
0876-hand-of-straights
0905-length-of-longest-fibonacci-subsequence
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0940-fruit-into-baskets
1160-letter-tile-possibilities
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1387-find-elements-in-a-contaminated-binary-tree
1460-number-of-substrings-containing-all-three-characters
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
1995-finding-pairs-with-a-certain-sum
2068-maximum-genetic-difference-query
2079-delete-duplicate-folders-in-system
2107-find-unique-binary-string
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2256-count-words-obtained-after-adding-a-letter
2308-divide-array-into-equal-pairs
2434-design-a-number-container-system
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2505-number-of-good-paths
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2626-count-the-number-of-good-subarrays
2685-first-completely-painted-row-or-column
2695-find-score-of-an-array-after-marking-all-elements
2707-merge-two-2d-arrays-by-summing-values
2766-find-the-prefix-common-array-of-two-arrays
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3197-maximum-strong-pair-xor-ii
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
3548-find-the-count-of-good-integers
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3707-find-the-most-common-response
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3771-select-k-disjoint-special-substrings
3788-maximum-unique-subarray-sum-after-deletion
3819-count-covered-buildings
3838-path-existence-queries-in-a-graph-i
3850-equal-sum-grid-partition-ii

Sorting

0015-3sum
0018-4sum
0075-sort-colors
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0368-largest-divisible-subset
0455-assign-cookies
0594-longest-harmonious-subsequence
0632-smallest-range-covering-elements-from-k-lists
0876-hand-of-straights
0982-minimum-increment-to-make-array-unique
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1669-minimum-cost-to-cut-a-stick
1851-maximum-number-of-events-that-can-be-attended-ii
2180-maximum-number-of-tasks-you-can-assign
2204-find-subsequence-of-length-k-with-the-largest-sum
2215-finding-3-digit-even-numbers
2256-count-words-obtained-after-adding-a-letter
2263-maximum-running-time-of-n-computers
2387-partition-array-such-that-maximum-difference-is-k
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2505-number-of-good-paths
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
3001-apply-operations-to-maximize-score
3219-make-lexicographically-smallest-array-by-swapping-elements
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3430-count-days-without-meetings
3647-zero-array-transformation-iii
3771-select-k-disjoint-special-substrings
3819-count-covered-buildings
3845-maximum-sum-of-edge-values-in-a-graph
3852-path-existence-queries-in-a-graph-ii
3859-maximum-product-of-two-digits
3959-maximum-total-from-optimal-activation-order

Heap (Priority Queue)

0218-the-skyline-problem
0239-sliding-window-maximum
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0407-trapping-rain-water-ii
0632-smallest-range-covering-elements-from-k-lists
1478-maximum-number-of-events-that-can-be-attended
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1753-path-with-minimum-effort
2204-find-subsequence-of-length-k-with-the-largest-sum
2267-minimum-difference-in-sums-after-removal-of-elements
2434-design-a-number-container-system
2449-maximum-number-of-robots-within-budget
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2479-meeting-rooms-iii
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
2695-find-score-of-an-array-after-marking-all-elements
2914-find-the-safest-path-in-a-grid
3445-lexicographically-minimum-string-after-removing-stars
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii
3655-digit-operations-to-make-two-integers-equal
3896-minimum-time-to-transport-all-individuals
3959-maximum-total-from-optimal-activation-order

Dynamic Programming

0042-trapping-rain-water
0118-pascals-triangle
0213-house-robber-ii
0337-house-robber-iii
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0516-longest-palindromic-subsequence
0600-non-negative-integers-without-consecutive-ones
0730-count-different-palindromic-subsequences
0806-domino-and-tromino-tiling
0823-split-array-with-same-average
0826-soup-servings
0867-new-21-game
0868-push-dominoes
0905-length-of-longest-fibonacci-subsequence
0934-bitwise-ors-of-subarrays
0954-maximum-sum-circular-subarray
1170-shortest-common-supersequence
1250-longest-common-subsequence
1348-maximum-score-of-spliced-array
1403-palindrome-partitioning-iii
1527-number-of-ways-to-paint-n-3-grid
1631-number-of-sub-arrays-with-odd-sum
1669-minimum-cost-to-cut-a-stick
1676-minimum-number-of-days-to-eat-n-oranges
1849-maximum-absolute-sum-of-any-subarray
1851-maximum-number-of-events-that-can-be-attended-ii
2028-the-earliest-and-latest-rounds-where-players-compete
2061-painting-a-grid-with-three-different-colors
2262-solving-questions-with-brainpower
2267-minimum-difference-in-sums-after-removal-of-elements
2395-longest-binary-subsequence-less-than-or-equal-to-k
2397-count-number-of-ways-to-place-houses
2415-count-the-number-of-ideal-arrays
2510-maximum-deletions-on-a-string
2577-count-palindromic-subsequences
2601-number-of-great-partitions
2739-minimize-the-total-price-of-the-trips
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3243-count-the-number-of-powerful-integers
3307-find-the-maximum-sum-of-node-values
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3532-time-taken-to-mark-all-nodes
3618-find-the-original-typed-string-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3648-find-the-maximum-number-of-fruits-collected
3649-minimum-time-to-break-locks-i
3686-count-beautiful-splits-in-an-array
3697-minimum-increments-for-target-multiples-in-an-array
3771-select-k-disjoint-special-substrings
3776-find-minimum-cost-to-remove-array-elements
3801-count-beautiful-numbers
3833-merge-operations-for-minimum-travel-time
3841-concatenated-divisibility
3851-find-sum-of-array-product-of-magical-sequences
3858-subtree-inversion-sum
3896-minimum-time-to-transport-all-individuals
3900-find-weighted-median-node-in-tree

Backtracking

0046-permutations
0126-word-ladder-ii
1160-letter-tile-possibilities
1819-construct-the-lexicographically-largest-valid-sequence
1993-sum-of-all-subset-xor-totals
2107-find-unique-binary-string
2140-longest-subsequence-repeated-k-times
2456-construct-smallest-number-from-di-string
2802-find-the-punishment-number-of-an-integer
3649-minimum-time-to-break-locks-i
3951-next-special-palindrome-number

Bit Manipulation

0342-power-of-four
0421-maximum-xor-of-two-numbers-in-an-array
0823-split-array-with-same-average
0934-bitwise-ors-of-subarrays
1826-maximum-xor-with-an-element-from-array
1993-sum-of-all-subset-xor-totals
2068-maximum-genetic-difference-query
2256-count-words-obtained-after-adding-a-letter
2308-divide-array-into-equal-pairs
2400-minimum-score-after-removals-on-a-tree
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
3197-maximum-strong-pair-xor-ii
3307-find-the-maximum-sum-of-node-values
3348-minimum-cost-walk-in-weighted-graph
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3649-minimum-time-to-break-locks-i
3697-minimum-increments-for-target-multiples-in-an-array
3841-concatenated-divisibility
3851-find-sum-of-array-product-of-magical-sequences
3896-minimum-time-to-transport-all-individuals

Bitmask

0823-split-array-with-same-average
3649-minimum-time-to-break-locks-i
3697-minimum-increments-for-target-multiples-in-an-array
3841-concatenated-divisibility
3851-find-sum-of-array-product-of-magical-sequences
3896-minimum-time-to-transport-all-individuals

Math

0009-palindrome-number
0060-permutation-sequence
0149-max-points-on-a-line
0326-power-of-three
0342-power-of-four
0368-largest-divisible-subset
0633-sum-of-square-numbers
0797-rabbits-in-forest
0823-split-array-with-same-average
0826-soup-servings
0867-new-21-game
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1477-product-of-the-last-k-numbers
1500-count-largest-group
1529-max-difference-you-can-get-from-changing-an-integer
1631-number-of-sub-arrays-with-odd-sum
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2202-sum-of-k-mirror-numbers
2415-count-the-number-of-ideal-arrays
2432-number-of-zero-filled-subarrays
2448-count-number-of-bad-pairs
2610-closest-prime-numbers-in-range
2649-count-total-number-of-colored-cells
2704-maximum-difference-by-remapping-a-digit
2802-find-the-punishment-number-of-an-integer
2998-count-symmetric-integers
3001-apply-operations-to-maximize-score
3172-divisible-and-non-divisible-sums-difference
3201-distribute-candies-among-children-ii
3243-count-the-number-of-powerful-integers
3321-type-of-triangle
3548-find-the-count-of-good-integers
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3637-count-number-of-balanced-permutations
3655-digit-operations-to-make-two-integers-equal
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements
3697-minimum-increments-for-target-multiples-in-an-array
3754-maximum-manhattan-distance-after-k-changes
3851-find-sum-of-array-product-of-magical-sequences
3859-maximum-product-of-two-digits
3882-partition-array-for-maximum-xor-and-and
3922-minimum-moves-to-reach-target-in-grid

Graph

0399-evaluate-division
0684-redundant-connection
0820-find-eventual-safe-states
0881-loud-and-rich
1300-critical-connections-in-a-network
1424-maximum-candies-you-can-get-from-boxes
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
2246-maximum-employees-to-be-invited-to-a-meeting
2438-find-closest-node-to-given-two-nodes
2505-number-of-good-paths
2564-most-profitable-path-in-a-tree
2583-divide-nodes-into-the-maximum-number-of-groups
2739-minimize-the-total-price-of-the-trips
2793-count-the-number-of-complete-components
3079-minimum-edge-weight-equilibrium-queries-in-a-tree
3348-minimum-cost-walk-in-weighted-graph
3532-time-taken-to-mark-all-nodes
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3655-digit-operations-to-make-two-integers-equal
3729-unit-conversion-i
3838-path-existence-queries-in-a-graph-i
3845-maximum-sum-of-edge-values-in-a-graph
3852-path-existence-queries-in-a-graph-ii
3896-minimum-time-to-transport-all-individuals

Number Theory

2415-count-the-number-of-ideal-arrays
2610-closest-prime-numbers-in-range
3001-apply-operations-to-maximize-score
3655-digit-operations-to-make-two-integers-equal
3697-minimum-increments-for-target-multiples-in-an-array

Shortest Path

0399-evaluate-division
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3655-digit-operations-to-make-two-integers-equal
3896-minimum-time-to-transport-all-individuals

Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0155-min-stack
0173-binary-search-tree-iterator
1050-construct-binary-search-tree-from-preorder-traversal
1818-maximum-score-from-removing-substrings
2021-remove-all-occurrences-of-a-substring
2221-check-if-a-parentheses-string-can-be-valid
2456-construct-smallest-number-from-di-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3001-apply-operations-to-maximize-score
3445-lexicographically-minimum-string-after-removing-stars
3447-clear-digits

Greedy

0135-candy
0455-assign-cookies
0632-smallest-range-covering-elements-from-k-lists
0797-rabbits-in-forest
0876-hand-of-straights
0982-minimum-increment-to-make-array-unique
1049-minimum-domino-rotations-for-equal-row
1478-maximum-number-of-events-that-can-be-attended
1529-max-difference-you-can-get-from-changing-an-integer
1818-maximum-score-from-removing-substrings
2140-longest-subsequence-repeated-k-times
2180-maximum-number-of-tasks-you-can-assign
2221-check-if-a-parentheses-string-can-be-valid
2237-longest-palindrome-by-concatenating-two-letter-words
2263-maximum-running-time-of-n-computers
2387-partition-array-such-that-maximum-difference-is-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2456-construct-smallest-number-from-di-string
2497-maximum-matching-of-players-with-trainers
2509-minimize-xor
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2681-put-marbles-in-bags
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3001-apply-operations-to-maximize-score
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii
3743-reschedule-meetings-for-maximum-free-time-i
3771-select-k-disjoint-special-substrings
3788-maximum-unique-subarray-sum-after-deletion
3845-maximum-sum-of-edge-values-in-a-graph
3852-path-existence-queries-in-a-graph-ii
3882-partition-array-for-maximum-xor-and-and
3959-maximum-total-from-optimal-activation-order

Brainteaser

2533-bitwise-xor-of-all-pairings

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0126-word-ladder-ii
0399-evaluate-division
0407-trapping-rain-water-ii
0662-maximum-width-of-binary-tree
0684-redundant-connection
0820-find-eventual-safe-states
0854-making-a-large-island
0945-snakes-and-ladders
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1424-maximum-candies-you-can-get-from-boxes
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
1753-path-with-minimum-effort
1876-map-of-highest-peak
2344-escape-the-spreading-fire
2564-most-profitable-path-in-a-tree
2583-divide-nodes-into-the-maximum-number-of-groups
2588-maximum-number-of-points-from-grid-queries
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components
2914-find-the-safest-path-in-a-grid
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3729-unit-conversion-i

Matrix

0073-set-matrix-zeroes
0407-trapping-rain-water-ii
0854-making-a-large-island
0945-snakes-and-ladders
1396-count-servers-that-communicate
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1753-path-with-minimum-effort
1876-map-of-highest-peak
2145-grid-game
2344-escape-the-spreading-fire
2588-maximum-number-of-points-from-grid-queries
2685-first-completely-painted-row-or-column
2764-maximum-number-of-fish-in-a-grid
2914-find-the-safest-path-in-a-grid
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3648-find-the-maximum-number-of-fruits-collected
3822-fill-a-special-grid
3850-equal-sum-grid-partition-ii
3973-flip-square-submatrix-vertically

Depth-First Search

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0211-design-add-and-search-words-data-structure
0236-lowest-common-ancestor-of-a-binary-tree
0337-house-robber-iii
0386-lexicographical-numbers
0399-evaluate-division
0662-maximum-width-of-binary-tree
0684-redundant-connection
0820-find-eventual-safe-states
0854-making-a-large-island
0881-loud-and-rich
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1300-critical-connections-in-a-network
1350-remove-sub-folders-from-the-filesystem
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1558-course-schedule-iv
1753-path-with-minimum-effort
2068-maximum-genetic-difference-query
2246-maximum-employees-to-be-invited-to-a-meeting
2400-minimum-score-after-removals-on-a-tree
2438-find-closest-node-to-given-two-nodes
2564-most-profitable-path-in-a-tree
2739-minimize-the-total-price-of-the-trips
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components
3532-time-taken-to-mark-all-nodes
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3729-unit-conversion-i
3845-maximum-sum-of-edge-values-in-a-graph
3858-subtree-inversion-sum
3900-find-weighted-median-node-in-tree

Union Find

0399-evaluate-division
0684-redundant-connection
0854-making-a-large-island
1058-lexicographically-smallest-equivalent-string
1396-count-servers-that-communicate
1753-path-with-minimum-effort
2505-number-of-good-paths
2583-divide-nodes-into-the-maximum-number-of-groups
2588-maximum-number-of-points-from-grid-queries
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components
2914-find-the-safest-path-in-a-grid
3219-make-lexicographically-smallest-array-by-swapping-elements
3348-minimum-cost-walk-in-weighted-graph
3838-path-existence-queries-in-a-graph-i

Counting

0347-top-k-frequent-elements
0594-longest-harmonious-subsequence
0982-minimum-increment-to-make-array-unique
1160-letter-tile-possibilities
1227-number-of-equivalent-domino-pairs
1364-tuple-with-same-product
1396-count-servers-that-communicate
1510-find-lucky-integer-in-an-array
1915-check-if-one-string-swap-can-make-strings-equal
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2308-divide-array-into-equal-pairs
2448-count-number-of-bad-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
3360-minimum-deletions-to-make-string-k-special
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3707-find-the-most-common-response
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Topological Sort

0820-find-eventual-safe-states
0881-loud-and-rich
1558-course-schedule-iv
2246-maximum-employees-to-be-invited-to-a-meeting

Design

0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0295-find-median-from-data-stream
0460-lfu-cache
0746-prefix-and-suffix-search
1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
1995-finding-pairs-with-a-certain-sum
2434-design-a-number-container-system

Ordered Set

0218-the-skyline-problem
2280-count-good-triplets-in-an-array
2434-design-a-number-container-system
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Rolling Hash

2510-maximum-deletions-on-a-string

Hash Function

2079-delete-duplicate-folders-in-system
2510-maximum-deletions-on-a-string

Data Stream

0295-find-median-from-data-stream
1477-product-of-the-last-k-numbers

Tree

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0173-binary-search-tree-iterator
0236-lowest-common-ancestor-of-a-binary-tree
0337-house-robber-iii
0662-maximum-width-of-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
1050-construct-binary-search-tree-from-preorder-traversal
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
2400-minimum-score-after-removals-on-a-tree
2505-number-of-good-paths
2564-most-profitable-path-in-a-tree
2739-minimize-the-total-price-of-the-trips
3079-minimum-edge-weight-equilibrium-queries-in-a-tree
3307-find-the-maximum-sum-of-node-values
3532-time-taken-to-mark-all-nodes
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3858-subtree-inversion-sum
3900-find-weighted-median-node-in-tree

Binary Tree

0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0173-binary-search-tree-iterator
0236-lowest-common-ancestor-of-a-binary-tree
0337-house-robber-iii
0662-maximum-width-of-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
1050-construct-binary-search-tree-from-preorder-traversal
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree

Divide and Conquer

0218-the-skyline-problem
0347-top-k-frequent-elements
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0954-maximum-sum-circular-subarray
2280-count-good-triplets-in-an-array
3822-fill-a-special-grid
3974-xor-after-range-multiplication-queries-i
3975-xor-after-range-multiplication-queries-ii

Sliding Window

0076-minimum-window-substring
0239-sliding-window-maximum
0594-longest-harmonious-subsequence
0632-smallest-range-covering-elements-from-k-lists
0867-new-21-game
0940-fruit-into-baskets
1460-number-of-substrings-containing-all-three-characters
1813-maximum-erasure-value
2394-count-subarrays-with-score-less-than-k
2449-maximum-number-of-robots-within-budget
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2527-count-subarrays-with-fixed-bounds
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3197-maximum-strong-pair-xor-ii
3213-count-subarrays-where-max-element-appears-at-least-k-times
3483-alternating-groups-ii
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3743-reschedule-meetings-for-maximum-free-time-i
3761-maximum-difference-between-even-and-odd-frequency-ii
3980-best-time-to-buy-and-sell-stock-using-strategy

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
1050-construct-binary-search-tree-from-preorder-traversal
3001-apply-operations-to-maximize-score

Combinatorics

1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays
3201-distribute-candies-among-children-ii
3548-find-the-count-of-good-integers
3637-count-number-of-balanced-permutations
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements
3851-find-sum-of-array-product-of-magical-sequences

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2140-longest-subsequence-repeated-k-times
2202-sum-of-k-mirror-numbers
2215-finding-3-digit-even-numbers
2998-count-symmetric-integers
3201-distribute-candies-among-children-ii
3548-find-the-count-of-good-integers
3683-find-the-lexicographically-largest-string-from-the-box-i
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair
3850-equal-sum-grid-partition-ii
3882-partition-array-for-maximum-xor-and-and

Recursion

0060-permutation-sequence
0326-power-of-three
0342-power-of-four
2050-count-good-numbers
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Binary Indexed Tree

0218-the-skyline-problem
2280-count-good-triplets-in-an-array

Segment Tree

0218-the-skyline-problem
2280-count-good-triplets-in-an-array
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Merge Sort

2280-count-good-triplets-in-an-array

Queue

0239-sliding-window-maximum
0954-maximum-sum-circular-subarray
2180-maximum-number-of-tasks-you-can-assign
2449-maximum-number-of-robots-within-budget
2527-count-subarrays-with-fixed-bounds

Monotonic Queue

0239-sliding-window-maximum
0954-maximum-sum-circular-subarray
2180-maximum-number-of-tasks-you-can-assign
2449-maximum-number-of-robots-within-budget
2527-count-subarrays-with-fixed-bounds

Trie

0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0386-lexicographical-numbers
0421-maximum-xor-of-two-numbers-in-an-array
0440-k-th-smallest-in-lexicographical-order
0746-prefix-and-suffix-search
1350-remove-sub-folders-from-the-filesystem
1826-maximum-xor-with-an-element-from-array
2068-maximum-genetic-difference-query
2079-delete-duplicate-folders-in-system
3197-maximum-strong-pair-xor-ii

Strongly Connected Component

3079-minimum-edge-weight-equilibrium-queries-in-a-tree

Database

0175-combine-two-tables
0176-second-highest-salary
0177-nth-highest-salary
0178-rank-scores
0180-consecutive-numbers
0184-department-highest-salary
1278-product-price-at-a-given-date

Memoization

1676-minimum-number-of-days-to-eat-n-oranges
2028-the-earliest-and-latest-rounds-where-players-compete
2395-longest-binary-subsequence-less-than-or-equal-to-k

Line Sweep

0218-the-skyline-problem

Geometry

0149-max-points-on-a-line

Concurrency

1187-print-foobar-alternately
1216-print-zero-even-odd
1316-fizz-buzz-multithreaded
1340-the-dining-philosophers

Linked List

0019-remove-nth-node-from-end-of-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0460-lfu-cache
1411-convert-binary-number-in-a-linked-list-to-integer

Doubly-Linked List

0146-lru-cache
0460-lfu-cache

Biconnected Component

1300-critical-connections-in-a-network

Bucket Sort

0347-top-k-frequent-elements

Quickselect

0347-top-k-frequent-elements

Binary Search Tree

0098-validate-binary-search-tree
0173-binary-search-tree-iterator
1050-construct-binary-search-tree-from-preorder-traversal

Iterator

0173-binary-search-tree-iterator

Probability and Statistics

0826-soup-servings
0867-new-21-game