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

LeetCode Topics

Hash Table

0049-group-anagrams
0073-set-matrix-zeroes
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0126-word-ladder-ii
0127-word-ladder
0133-clone-graph
0139-word-break
0242-valid-anagram
0264-ugly-number-ii
0442-find-all-duplicates-in-an-array
0508-most-frequent-subtree-sum
0523-continuous-subarray-sum
0525-contiguous-array
0653-two-sum-iv-input-is-a-bst
0721-accounts-merge
0797-rabbits-in-forest
0869-similar-string-groups
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1023-time-based-key-value-store
1218-lowest-common-ancestor-of-deepest-leaves
1227-number-of-equivalent-domino-pairs
1370-count-number-of-nice-subarrays
1500-count-largest-group
1510-find-lucky-integer-in-an-array
1986-largest-color-value-in-a-directed-graph
1995-finding-pairs-with-a-certain-sum
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2461-amount-of-time-for-binary-tree-to-be-infected
2626-count-the-number-of-good-subarrays
2640-maximum-number-of-integers-to-choose-from-a-range-i
2689-rearranging-fruits
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3548-find-the-count-of-good-integers
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
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3777-maximum-product-of-subsequences-with-an-alternating-sum-equal-to-k
3813-smallest-palindromic-rearrangement-ii

Tree

0095-unique-binary-search-trees-ii
0096-unique-binary-search-trees
0099-recover-binary-search-tree
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0107-binary-tree-level-order-traversal-ii
0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0124-binary-tree-maximum-path-sum
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0331-verify-preorder-serialization-of-a-binary-tree
0337-house-robber-iii
0449-serialize-and-deserialize-bst
0508-most-frequent-subtree-sum
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0543-diameter-of-binary-tree
0606-construct-string-from-binary-tree
0617-merge-two-binary-trees
0653-two-sum-iv-input-is-a-bst
0654-maximum-binary-tree
0662-maximum-width-of-binary-tree
0669-trim-a-binary-search-tree
0687-longest-univalue-path
0764-n-ary-tree-level-order-traversal
0783-search-in-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0832-binary-tree-pruning
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
0930-all-possible-full-binary-trees
0955-complete-binary-tree-inserter
1040-maximum-binary-tree-ii
1092-maximum-difference-between-node-and-ancestor
1114-binary-search-tree-to-greater-sum-tree
1116-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1243-sum-of-nodes-with-even-valued-grandparent
1254-deepest-leaves-sum
1285-balance-a-binary-search-tree
1427-all-elements-in-two-binary-search-trees
1465-maximum-product-of-splitted-binary-tree
1475-maximum-sum-bst-in-binary-tree
1544-count-good-nodes-in-binary-tree
1731-even-odd-tree
2347-count-nodes-equal-to-average-of-subtree
2384-root-equals-sum-of-children
2416-evaluate-boolean-binary-tree
2461-amount-of-time-for-binary-tree-to-be-infected
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2567-closest-nodes-queries-in-a-binary-search-tree
2568-minimum-fuel-cost-to-report-to-the-capital
2646-kth-largest-sum-in-a-binary-tree
2780-make-costs-of-paths-equal-in-a-binary-tree
3307-find-the-maximum-sum-of-node-values
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Depth-First Search

0099-recover-binary-search-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0124-binary-tree-maximum-path-sum
0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0337-house-robber-iii
0365-water-and-jug-problem
0386-lexicographical-numbers
0419-battleships-in-a-board
0449-serialize-and-deserialize-bst
0508-most-frequent-subtree-sum
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0543-diameter-of-binary-tree
0606-construct-string-from-binary-tree
0617-merge-two-binary-trees
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0669-trim-a-binary-search-tree
0684-redundant-connection
0687-longest-univalue-path
0721-accounts-merge
0744-network-delay-time
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
0832-binary-tree-pruning
0854-making-a-large-island
0869-similar-string-groups
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
1073-number-of-enclaves
1092-maximum-difference-between-node-and-ancestor
1114-binary-search-tree-to-greater-sum-tree
1116-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1243-sum-of-nodes-with-even-valued-grandparent
1254-deepest-leaves-sum
1285-balance-a-binary-search-tree
1350-remove-sub-folders-from-the-filesystem
1380-number-of-closed-islands
1427-all-elements-in-two-binary-search-trees
1465-maximum-product-of-splitted-binary-tree
1475-maximum-sum-bst-in-binary-tree
1544-count-good-nodes-in-binary-tree
1753-path-with-minimum-effort
2347-count-nodes-equal-to-average-of-subtree
2416-evaluate-boolean-binary-tree
2438-find-closest-node-to-given-two-nodes
2461-amount-of-time-for-binary-tree-to-be-infected
2493-reverse-odd-levels-of-binary-tree
2567-closest-nodes-queries-in-a-binary-search-tree
2568-minimum-fuel-cost-to-report-to-the-capital
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Breadth-First Search

0107-binary-tree-level-order-traversal-ii
0111-minimum-depth-of-binary-tree
0112-path-sum
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0126-word-ladder-ii
0127-word-ladder
0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0279-perfect-squares
0297-serialize-and-deserialize-binary-tree
0322-coin-change
0365-water-and-jug-problem
0449-serialize-and-deserialize-bst
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0617-merge-two-binary-trees
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0684-redundant-connection
0721-accounts-merge
0744-network-delay-time
0764-n-ary-tree-level-order-traversal
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
0854-making-a-large-island
0869-similar-string-groups
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
0945-snakes-and-ladders
0955-complete-binary-tree-inserter
1007-numbers-with-same-consecutive-differences
1073-number-of-enclaves
1116-maximum-level-sum-of-a-binary-tree
1117-as-far-from-land-as-possible
1171-shortest-path-in-binary-matrix
1218-lowest-common-ancestor-of-deepest-leaves
1243-sum-of-nodes-with-even-valued-grandparent
1254-deepest-leaves-sum
1380-number-of-closed-islands
1544-count-good-nodes-in-binary-tree
1731-even-odd-tree
1753-path-with-minimum-effort
2461-amount-of-time-for-binary-tree-to-be-infected
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2568-minimum-fuel-cost-to-report-to-the-capital
2646-kth-largest-sum-in-a-binary-tree
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Binary Tree

0095-unique-binary-search-trees-ii
0096-unique-binary-search-trees
0099-recover-binary-search-tree
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0107-binary-tree-level-order-traversal-ii
0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0124-binary-tree-maximum-path-sum
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0297-serialize-and-deserialize-binary-tree
0331-verify-preorder-serialization-of-a-binary-tree
0337-house-robber-iii
0449-serialize-and-deserialize-bst
0508-most-frequent-subtree-sum
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0543-diameter-of-binary-tree
0606-construct-string-from-binary-tree
0617-merge-two-binary-trees
0653-two-sum-iv-input-is-a-bst
0654-maximum-binary-tree
0662-maximum-width-of-binary-tree
0669-trim-a-binary-search-tree
0687-longest-univalue-path
0783-search-in-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0832-binary-tree-pruning
0893-all-nodes-distance-k-in-binary-tree
0896-smallest-subtree-with-all-the-deepest-nodes
0930-all-possible-full-binary-trees
0955-complete-binary-tree-inserter
1040-maximum-binary-tree-ii
1092-maximum-difference-between-node-and-ancestor
1114-binary-search-tree-to-greater-sum-tree
1116-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1243-sum-of-nodes-with-even-valued-grandparent
1254-deepest-leaves-sum
1285-balance-a-binary-search-tree
1427-all-elements-in-two-binary-search-trees
1465-maximum-product-of-splitted-binary-tree
1475-maximum-sum-bst-in-binary-tree
1544-count-good-nodes-in-binary-tree
1731-even-odd-tree
2347-count-nodes-equal-to-average-of-subtree
2384-root-equals-sum-of-children
2416-evaluate-boolean-binary-tree
2461-amount-of-time-for-binary-tree-to-be-infected
2493-reverse-odd-levels-of-binary-tree
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2567-closest-nodes-queries-in-a-binary-search-tree
2646-kth-largest-sum-in-a-binary-tree
2780-make-costs-of-paths-equal-in-a-binary-tree

Array

0015-3sum
0027-remove-element
0035-search-insert-position
0049-group-anagrams
0054-spiral-matrix
0073-set-matrix-zeroes
0075-sort-colors
0090-subsets-ii
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0139-word-break
0154-find-minimum-in-rotated-sorted-array-ii
0198-house-robber
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0238-product-of-array-except-self
0275-h-index-ii
0304-range-sum-query-2d-immutable
0322-coin-change
0368-largest-divisible-subset
0384-shuffle-an-array
0416-partition-equal-subset-sum
0419-battleships-in-a-board
0442-find-all-duplicates-in-an-array
0523-continuous-subarray-sum
0525-contiguous-array
0540-single-element-in-a-sorted-array
0654-maximum-binary-tree
0721-accounts-merge
0792-binary-search
0794-swim-in-rising-water
0797-rabbits-in-forest
0854-making-a-large-island
0869-similar-string-groups
0909-stone-game
0917-boats-to-save-people
0940-fruit-into-baskets
0945-snakes-and-ladders
0966-binary-subarrays-with-sum
1009-pancake-sorting
1020-longest-turbulent-subarray
1032-satisfiability-of-equality-equations
1046-max-consecutive-ones-iii
1049-minimum-domino-rotations-for-equal-row
1073-number-of-enclaves
1117-as-far-from-land-as-possible
1171-shortest-path-in-binary-matrix
1227-number-of-equivalent-domino-pairs
1293-three-consecutive-odds
1350-remove-sub-folders-from-the-filesystem
1370-count-number-of-nice-subarrays
1380-number-of-closed-islands
1421-find-numbers-with-even-number-of-digits
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1538-maximum-points-you-can-obtain-from-cards
1615-range-sum-of-sorted-subarray-sums
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1656-count-good-triplets
1706-min-cost-to-connect-all-points
1753-path-with-minimum-effort
1762-furthest-building-you-can-reach
1803-average-waiting-time
1886-minimum-limit-of-balls-in-a-bag
1951-find-the-winner-of-the-circular-game
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2000-minimum-speed-to-arrive-on-time
2048-build-array-from-permutation
2113-find-the-kth-largest-integer-in-the-array
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2237-longest-palindrome-by-concatenating-two-letter-words
2249-count-the-hidden-sequences
2277-count-equal-and-divisible-pairs-in-an-array
2280-count-good-triplets-in-an-array
2394-count-subarrays-with-score-less-than-k
2437-maximum-number-of-groups-entering-a-competition
2472-build-a-matrix-with-conditions
2497-maximum-matching-of-players-with-trainers
2527-count-subarrays-with-fixed-bounds
2530-minimize-maximum-of-array
2567-closest-nodes-queries-in-a-binary-search-tree
2600-maximum-tastiness-of-candy-basket
2601-number-of-great-partitions
2606-difference-between-ones-and-zeros-in-row-and-column
2626-count-the-number-of-good-subarrays
2640-maximum-number-of-integers-to-choose-from-a-range-i
2689-rearranging-fruits
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
2780-make-costs-of-paths-equal-in-a-binary-tree
2856-count-complete-subarrays-in-an-array
2915-count-of-interesting-subarrays
3142-longest-unequal-adjacent-groups-subsequence-ii
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3194-find-words-containing-character
3213-count-subarrays-where-max-element-appears-at-least-k-times
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3435-block-placement-queries
3527-alternating-groups-iii
3550-maximum-value-sum-by-placing-three-rooks-i
3556-final-array-state-after-k-multiplication-operations-ii
3563-select-cells-in-grid-with-maximum-score
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
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3658-minimize-the-maximum-adjacent-element-difference
3685-count-subarrays-of-length-three-with-a-condition
3741-reschedule-meetings-for-maximum-free-time-ii
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3777-maximum-product-of-subsequences-with-an-alternating-sum-equal-to-k

Math

0029-divide-two-integers
0096-unique-binary-search-trees
0264-ugly-number-ii
0279-perfect-squares
0319-bulb-switcher
0365-water-and-jug-problem
0368-largest-divisible-subset
0384-shuffle-an-array
0390-elimination-game
0523-continuous-subarray-sum
0795-k-th-symbol-in-grammar
0797-rabbits-in-forest
0909-stone-game
1013-fibonacci-number
1370-count-number-of-nice-subarrays
1411-convert-binary-number-in-a-linked-list-to-integer
1421-find-numbers-with-even-number-of-digits
1500-count-largest-group
1951-find-the-winner-of-the-circular-game
1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays
2437-maximum-number-of-groups-entering-a-competition
2645-pass-the-pillow
2704-maximum-difference-by-remapping-a-digit
2998-count-symmetric-integers
3172-divisible-and-non-divisible-sums-difference
3243-count-the-number-of-powerful-integers
3270-minimum-moves-to-capture-the-queen
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
3754-maximum-manhattan-distance-after-k-changes
3774-check-if-digits-are-equal-in-string-after-operations-ii
3813-smallest-palindromic-rearrangement-ii
3922-minimum-moves-to-reach-target-in-grid

Backtracking

0090-subsets-ii
0095-unique-binary-search-trees-ii
0113-path-sum-ii
0126-word-ladder-ii
1007-numbers-with-same-consecutive-differences
1993-sum-of-all-subset-xor-totals

Bit Manipulation

0029-divide-two-integers
0090-subsets-ii
0795-k-th-symbol-in-grammar
1993-sum-of-all-subset-xor-totals
2276-groups-of-strings
3307-find-the-maximum-sum-of-node-values
3563-select-cells-in-grid-with-maximum-score
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Combinatorics

1993-sum-of-all-subset-xor-totals
2415-count-the-number-of-ideal-arrays
3548-find-the-count-of-good-integers
3637-count-number-of-balanced-permutations
3774-check-if-digits-are-equal-in-string-after-operations-ii
3813-smallest-palindromic-rearrangement-ii

Enumeration

1656-count-good-triplets
1993-sum-of-all-subset-xor-totals
2215-finding-3-digit-even-numbers
2998-count-symmetric-integers
3270-minimum-moves-to-capture-the-queen
3548-find-the-count-of-good-integers
3550-maximum-value-sum-by-placing-three-rooks-i
3741-reschedule-meetings-for-maximum-free-time-ii
3761-maximum-difference-between-even-and-odd-frequency-ii

String

0038-count-and-say
0049-group-anagrams
0087-scramble-string
0126-word-ladder-ii
0127-word-ladder
0139-word-break
0242-valid-anagram
0297-serialize-and-deserialize-binary-tree
0331-verify-preorder-serialization-of-a-binary-tree
0420-strong-password-checker
0449-serialize-and-deserialize-bst
0606-construct-string-from-binary-tree
0721-accounts-merge
0868-push-dominoes
0869-similar-string-groups
0957-minimum-add-to-make-parentheses-valid
1023-time-based-key-value-store
1032-satisfiability-of-equality-equations
1058-lexicographically-smallest-equivalent-string
1350-remove-sub-folders-from-the-filesystem
2113-find-the-kth-largest-integer-in-the-array
2134-maximize-the-confusion-of-an-exam
2237-longest-palindrome-by-concatenating-two-letter-words
2276-groups-of-strings
2470-removing-stars-from-a-string
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
3396-valid-word
3580-find-the-occurrence-of-first-almost-equal-substring
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
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
3774-check-if-digits-are-equal-in-string-after-operations-ii
3808-longest-palindrome-after-substring-concatenation-ii
3813-smallest-palindromic-rearrangement-ii

Sorting

0015-3sum
0049-group-anagrams
0075-sort-colors
0215-kth-largest-element-in-an-array
0242-valid-anagram
0368-largest-divisible-subset
0721-accounts-merge
0917-boats-to-save-people
1009-pancake-sorting
1427-all-elements-in-two-binary-search-trees
1478-maximum-number-of-events-that-can-be-attended
1613-find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
1615-range-sum-of-sorted-subarray-sums
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2113-find-the-kth-largest-integer-in-the-array
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2215-finding-3-digit-even-numbers
2497-maximum-matching-of-players-with-trainers
2600-maximum-tastiness-of-candy-basket
2640-maximum-number-of-integers-to-choose-from-a-range-i
2646-kth-largest-sum-in-a-binary-tree
2689-rearranging-fruits
2699-count-the-number-of-fair-pairs
3241-divide-array-into-arrays-with-max-difference
3307-find-the-maximum-sum-of-node-values
3321-type-of-triangle
3647-zero-array-transformation-iii

Design

0297-serialize-and-deserialize-binary-tree
0304-range-sum-query-2d-immutable
0384-shuffle-an-array
0449-serialize-and-deserialize-bst
0789-kth-largest-element-in-a-stream
0955-complete-binary-tree-inserter
1023-time-based-key-value-store
1995-finding-pairs-with-a-certain-sum

Matrix

0054-spiral-matrix
0073-set-matrix-zeroes
0304-range-sum-query-2d-immutable
0419-battleships-in-a-board
0794-swim-in-rising-water
0854-making-a-large-island
0945-snakes-and-ladders
1073-number-of-enclaves
1117-as-far-from-land-as-possible
1171-shortest-path-in-binary-matrix
1380-number-of-closed-islands
1753-path-with-minimum-effort
2472-build-a-matrix-with-conditions
2606-difference-between-ones-and-zeros-in-row-and-column
3550-maximum-value-sum-by-placing-three-rooks-i
3563-select-cells-in-grid-with-maximum-score
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Prefix Sum

0238-product-of-array-except-self
0304-range-sum-query-2d-immutable
0523-continuous-subarray-sum
0525-contiguous-array
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards
1615-range-sum-of-sorted-subarray-sums
2134-maximize-the-confusion-of-an-exam
2249-count-the-hidden-sequences
2394-count-subarrays-with-score-less-than-k
2530-minimize-maximum-of-array
2915-count-of-interesting-subarrays
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

Sliding Window

0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1020-longest-turbulent-subarray
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards
2134-maximize-the-confusion-of-an-exam
2394-count-subarrays-with-score-less-than-k
2527-count-subarrays-with-fixed-bounds
2626-count-the-number-of-good-subarrays
2856-count-complete-subarrays-in-an-array
3213-count-subarrays-where-max-element-appears-at-least-k-times
3761-maximum-difference-between-even-and-odd-frequency-ii

Two Pointers

0015-3sum
0027-remove-element
0075-sort-colors
0143-reorder-list
0653-two-sum-iv-input-is-a-bst
0868-push-dominoes
0917-boats-to-save-people
1009-pancake-sorting
1615-range-sum-of-sorted-subarray-sums
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2497-maximum-matching-of-players-with-trainers
2699-count-the-number-of-fair-pairs
3808-longest-palindrome-after-substring-concatenation-ii

Greedy

0420-strong-password-checker
0797-rabbits-in-forest
0917-boats-to-save-people
0957-minimum-add-to-make-parentheses-valid
1009-pancake-sorting
1049-minimum-domino-rotations-for-equal-row
1285-balance-a-binary-search-tree
1478-maximum-number-of-events-that-can-be-attended
1762-furthest-building-you-can-reach
2180-maximum-number-of-tasks-you-can-assign
2237-longest-palindrome-by-concatenating-two-letter-words
2437-maximum-number-of-groups-entering-a-competition
2497-maximum-matching-of-players-with-trainers
2530-minimize-maximum-of-array
2600-maximum-tastiness-of-candy-basket
2640-maximum-number-of-integers-to-choose-from-a-range-i
2689-rearranging-fruits
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
2780-make-costs-of-paths-equal-in-a-binary-tree
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
3647-zero-array-transformation-iii
3658-minimize-the-maximum-adjacent-element-difference
3741-reschedule-meetings-for-maximum-free-time-ii

Binary Search

0035-search-insert-position
0154-find-minimum-in-rotated-sorted-array-ii
0275-h-index-ii
0540-single-element-in-a-sorted-array
0792-binary-search
0794-swim-in-rising-water
1023-time-based-key-value-store
1046-max-consecutive-ones-iii
1615-range-sum-of-sorted-subarray-sums
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1753-path-with-minimum-effort
1886-minimum-limit-of-balls-in-a-bag
2000-minimum-speed-to-arrive-on-time
2134-maximize-the-confusion-of-an-exam
2179-most-beautiful-item-for-each-query
2180-maximum-number-of-tasks-you-can-assign
2280-count-good-triplets-in-an-array
2394-count-subarrays-with-score-less-than-k
2437-maximum-number-of-groups-entering-a-competition
2530-minimize-maximum-of-array
2567-closest-nodes-queries-in-a-binary-search-tree
2600-maximum-tastiness-of-candy-basket
2640-maximum-number-of-integers-to-choose-from-a-range-i
2699-count-the-number-of-fair-pairs
2720-minimize-the-maximum-difference-of-pairs
3435-block-placement-queries
3658-minimize-the-maximum-adjacent-element-difference

Dynamic Programming

0087-scramble-string
0095-unique-binary-search-trees-ii
0096-unique-binary-search-trees
0118-pascals-triangle
0124-binary-tree-maximum-path-sum
0139-word-break
0198-house-robber
0213-house-robber-ii
0264-ugly-number-ii
0279-perfect-squares
0322-coin-change
0337-house-robber-iii
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0803-cheapest-flights-within-k-stops
0806-domino-and-tromino-tiling
0868-push-dominoes
0909-stone-game
0930-all-possible-full-binary-trees
1013-fibonacci-number
1020-longest-turbulent-subarray
1117-as-far-from-land-as-possible
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1475-maximum-sum-bst-in-binary-tree
1986-largest-color-value-in-a-directed-graph
2415-count-the-number-of-ideal-arrays
2530-minimize-maximum-of-array
2601-number-of-great-partitions
2780-make-costs-of-paths-equal-in-a-binary-tree
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
3550-maximum-value-sum-by-placing-three-rooks-i
3563-select-cells-in-grid-with-maximum-score
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
3777-maximum-product-of-subsequences-with-an-alternating-sum-equal-to-k
3808-longest-palindrome-after-substring-concatenation-ii

Randomized

0384-shuffle-an-array

Divide and Conquer

0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0215-kth-largest-element-in-an-array
0654-maximum-binary-tree
1285-balance-a-binary-search-tree
2113-find-the-kth-largest-integer-in-the-array
2280-count-good-triplets-in-an-array

Binary Indexed Tree

2280-count-good-triplets-in-an-array
3435-block-placement-queries
3527-alternating-groups-iii

Segment Tree

2280-count-good-triplets-in-an-array
3435-block-placement-queries

Merge Sort

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

Ordered Set

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

Linked List

0109-convert-sorted-list-to-binary-search-tree
0116-populating-next-right-pointers-in-each-node
0117-populating-next-right-pointers-in-each-node-ii
0143-reorder-list
1411-convert-binary-number-in-a-linked-list-to-integer

Binary Search Tree

0095-unique-binary-search-trees-ii
0096-unique-binary-search-trees
0099-recover-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0109-convert-sorted-list-to-binary-search-tree
0449-serialize-and-deserialize-bst
0653-two-sum-iv-input-is-a-bst
0669-trim-a-binary-search-tree
0783-search-in-a-binary-search-tree
0789-kth-largest-element-in-a-stream
1114-binary-search-tree-to-greater-sum-tree
1285-balance-a-binary-search-tree
1427-all-elements-in-two-binary-search-trees
1475-maximum-sum-bst-in-binary-tree
2567-closest-nodes-queries-in-a-binary-search-tree

Number Theory

2415-count-the-number-of-ideal-arrays
3774-check-if-digits-are-equal-in-string-after-operations-ii

Stack

0143-reorder-list
0331-verify-preorder-serialization-of-a-binary-tree
0654-maximum-binary-tree
0957-minimum-add-to-make-parentheses-valid
2470-removing-stars-from-a-string

Queue

1951-find-the-winner-of-the-circular-game
2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Monotonic Queue

2180-maximum-number-of-tasks-you-can-assign
2527-count-subarrays-with-fixed-bounds

Recursion

0143-reorder-list
0390-elimination-game
0795-k-th-symbol-in-grammar
0930-all-possible-full-binary-trees
1013-fibonacci-number
1951-find-the-winner-of-the-circular-game
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

Union Find

0684-redundant-connection
0721-accounts-merge
0794-swim-in-rising-water
0854-making-a-large-island
0869-similar-string-groups
1032-satisfiability-of-equality-equations
1058-lexicographically-smallest-equivalent-string
1073-number-of-enclaves
1380-number-of-closed-islands
1613-find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
1706-min-cost-to-connect-all-points
1753-path-with-minimum-effort
2276-groups-of-strings

Graph

0133-clone-graph
0207-course-schedule
0210-course-schedule-ii
0684-redundant-connection
0744-network-delay-time
0803-cheapest-flights-within-k-stops
1032-satisfiability-of-equality-equations
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1613-find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
1701-remove-max-number-of-edges-to-keep-graph-fully-traversable
1706-min-cost-to-connect-all-points
1986-largest-color-value-in-a-directed-graph
2438-find-closest-node-to-given-two-nodes
2472-build-a-matrix-with-conditions
2568-minimum-fuel-cost-to-report-to-the-capital
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Topological Sort

0207-course-schedule
0210-course-schedule-ii
1986-largest-color-value-in-a-directed-graph
2472-build-a-matrix-with-conditions

Counting

1227-number-of-equivalent-domino-pairs
1510-find-lucky-integer-in-an-array
1986-largest-color-value-in-a-directed-graph
2237-longest-palindrome-by-concatenating-two-letter-words
3629-total-characters-in-string-after-transformations-i
3630-total-characters-in-string-after-transformations-ii
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3813-smallest-palindromic-rearrangement-ii

Simulation

0054-spiral-matrix
1803-average-waiting-time
1951-find-the-winner-of-the-circular-game
2048-build-array-from-permutation
2470-removing-stars-from-a-string
2606-difference-between-ones-and-zeros-in-row-and-column
2645-pass-the-pillow
3556-final-array-state-after-k-multiplication-operations-ii
3600-find-the-k-th-character-in-string-game-i

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0264-ugly-number-ii
0420-strong-password-checker
0744-network-delay-time
0789-kth-largest-element-in-a-stream
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
1478-maximum-number-of-events-that-can-be-attended
1753-path-with-minimum-effort
1762-furthest-building-you-can-reach
2113-find-the-kth-largest-integer-in-the-array
3556-final-array-state-after-k-multiplication-operations-ii
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii
3647-zero-array-transformation-iii

Shortest Path

0744-network-delay-time
0803-cheapest-flights-within-k-stops
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
3627-find-minimum-time-to-reach-last-room-i
3628-find-minimum-time-to-reach-last-room-ii

Memoization

0139-word-break
0930-all-possible-full-binary-trees
1013-fibonacci-number
1986-largest-color-value-in-a-directed-graph

Game Theory

0909-stone-game

Trie

0139-word-break
0386-lexicographical-numbers
1350-remove-sub-folders-from-the-filesystem

String Matching

3580-find-the-occurrence-of-first-almost-equal-substring

Bitmask

3563-select-cells-in-grid-with-maximum-score

Database

0175-combine-two-tables
0177-nth-highest-salary
0178-rank-scores

Brainteaser

0319-bulb-switcher

Monotonic Stack

0654-maximum-binary-tree

Data Stream

0789-kth-largest-element-in-a-stream

Quickselect

0215-kth-largest-element-in-an-array
2113-find-the-kth-largest-integer-in-the-array

Minimum Spanning Tree

1613-find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree
1706-min-cost-to-connect-all-points

Strongly Connected Component

1613-find-critical-and-pseudo-critical-edges-in-minimum-spanning-tree