Leetcode-problem

A collection of LeetCode questions to ace the coding interview!

LeetCode Topics

Array


0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0039-combination-sum
0040-combination-sum-ii
0045-jump-game-ii
0046-permutations
0048-rotate-image
0049-group-anagrams
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0066-plus-one
0073-set-matrix-zeroes
0075-sort-colors
0078-subsets
0079-word-search
0081-search-in-rotated-sorted-array-ii
0088-merge-sorted-array
0090-subsets-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0130-surrounded-regions
0135-candy
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0179-largest-number
0198-house-robber
0204-count-primes
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0238-product-of-array-except-self
0239-sliding-window-maximum
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0407-trapping-rain-water-ii
0455-assign-cookies
0494-target-sum
0496-next-greater-element-i
0503-next-greater-element-ii
0539-minimum-time-difference
0540-single-element-in-a-sorted-array
0542-01-matrix
0621-task-scheduler
0624-maximum-distance-in-arrays
0632-smallest-range-covering-elements-from-k-lists
0719-find-k-th-smallest-pair-distance
0724-find-pivot-index
0729-my-calendar-i
0731-my-calendar-ii
0733-flood-fill
0735-asteroid-collision
0739-daily-temperatures
0780-max-chunks-to-make-sorted
0787-sliding-puzzle
0792-binary-search
0854-making-a-large-island
0859-design-circular-deque
0870-magic-squares-in-grid
0876-hand-of-straights
0883-car-fleet
0890-lemonade-change
0892-shortest-subarray-with-sum-at-least-k
0906-walking-robot-simulation
0907-koko-eating-bananas
0909-stone-game
0921-spiral-matrix-iii
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0945-snakes-and-ladders
0948-sort-an-array
0952-word-subsets
0999-regions-cut-by-slashes
1002-maximum-width-ramp
1014-k-closest-points-to-origin
1025-minimum-cost-for-tickets
1036-rotting-oranges
1050-construct-binary-search-tree-from-preorder-traversal
1056-capacity-to-ship-packages-within-d-days
1063-best-sightseeing-pair
1073-number-of-enclaves
1127-last-stone-weight
1147-flip-columns-for-maximum-number-of-equal-rows
1171-shortest-path-in-binary-matrix
1196-filling-bookcase-shelves
1207-delete-nodes-and-return-forest
1240-stone-game-ii
1256-rank-transform-of-an-array
1293-three-consecutive-odds
1325-path-with-maximum-probability
1333-sort-the-jumbled-numbers
1335-maximum-candies-allocated-to-k-children
1350-remove-sub-folders-from-the-filesystem
1364-tuple-with-same-product
1402-count-square-submatrices-with-all-ones
1422-divide-array-in-sets-of-k-consecutive-numbers
1424-maximum-candies-you-can-get-from-boxes
1435-xor-queries-of-a-subarray
1463-the-k-weakest-rows-in-a-matrix
1468-check-if-n-and-its-double-exist
1477-product-of-the-last-k-numbers
1483-rank-teams-by-votes
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1496-lucky-numbers-in-a-matrix
1497-design-a-stack-with-increment-operation
1511-count-number-of-teams
1524-string-matching-in-an-array
1556-make-two-arrays-equal-by-reversing-subarrays
1570-final-prices-with-a-special-discount-in-a-shop
1605-minimum-number-of-days-to-make-m-bouquets
1615-range-sum-of-sorted-subarray-sums
1620-check-if-array-pairs-are-divisible-by-k
1631-number-of-sub-arrays-with-odd-sum
1646-kth-missing-positive-number
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1691-minimum-number-of-days-to-disconnect-island
1694-make-sum-divisible-by-p
1711-find-valid-matrix-given-row-and-column-sums
1741-sort-array-by-increasing-frequency
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1753-path-with-minimum-effort
1755-defuse-the-bomb
1766-minimum-number-of-removals-to-make-mountain-array
1786-count-the-number-of-consistent-strings
1819-construct-the-lexicographically-largest-valid-sequence
1829-maximum-units-on-a-truck
1876-map-of-highest-peak
1878-check-if-array-is-sorted-and-rotated
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1917-maximum-average-pass-ratio
1923-sentence-similarity-iii
1927-maximum-ascending-subarray-sum
1940-maximum-xor-for-each-query
1972-rotating-the-box
1993-sum-of-all-subset-xor-totals
2006-find-the-student-that-will-replace-the-chalk
2035-count-sub-islands
2054-the-number-of-the-smallest-unoccupied-chair
2067-maximum-number-of-points-with-cost
2089-maximum-matrix-sum
2102-find-the-middle-index-in-array
2106-find-greatest-common-divisor-of-array
2107-find-unique-binary-string
2132-convert-1d-array-into-2d-array
2144-maximum-difference-between-increasing-elements
2145-grid-game
2150-kth-smallest-product-of-two-sorted-arrays
2155-find-missing-observations
2163-kth-distinct-string-in-an-array
2164-two-best-non-overlapping-events
2170-count-number-of-maximum-bitwise-or-subsets
2179-most-beautiful-item-for-each-query
2188-minimized-maximum-of-products-distributed-to-any-store
2215-finding-3-digit-even-numbers
2227-sum-of-subarray-ranges
2232-adding-spaces-to-a-string
2255-minimum-swaps-to-group-all-1s-together-ii
2265-partition-array-according-to-given-pivot
2277-count-equal-and-divisible-pairs-in-an-array
2292-counting-words-with-a-given-prefix
2320-find-all-k-distant-indices-in-an-array
2324-find-triangular-sum-of-an-array
2343-count-unguarded-cells-in-the-grid
2358-number-of-ways-to-split-array
2375-minimum-obstacle-removal-to-reach-corner
2387-partition-array-such-that-maximum-difference-is-k
2411-spiral-matrix-iv
2436-make-array-zero-by-subtracting-equal-amounts
2448-count-number-of-bad-pairs
2465-shifting-letters-ii
2472-build-a-matrix-with-conditions
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2488-divide-intervals-into-minimum-number-of-groups
2494-sum-of-prefix-scores-of-strings
2497-maximum-matching-of-players-with-trainers
2502-sort-the-people
2503-longest-subarray-with-maximum-bitwise-and
2533-bitwise-xor-of-all-pairings
2545-height-of-binary-tree-after-subtree-removal-queries
2551-apply-operations-to-an-array
2552-maximum-sum-of-distinct-subarrays-with-length-k
2554-minimum-total-distance-traveled
2564-most-profitable-path-in-a-tree
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
2665-minimum-time-to-repair-cars
2685-first-completely-painted-row-or-column
2691-count-vowel-strings-in-ranges
2692-take-gifts-from-the-richest-pile
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
2716-prime-subtraction-operation
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2764-maximum-number-of-fish-in-a-grid
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
2794-maximum-number-of-moves-in-a-grid
2856-count-complete-subarrays-in-an-array
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
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
3181-find-building-where-alice-and-bob-can-meet
3194-find-words-containing-character
3219-make-lexicographically-smallest-array-by-swapping-elements
3227-find-missing-and-repeated-values
3235-minimum-cost-to-convert-string-i
3241-divide-array-into-arrays-with-max-difference
3291-find-if-array-can-be-sorted
3309-count-prefix-and-suffix-pairs-i
3321-type-of-triangle
3329-find-the-length-of-the-longest-common-prefix
3380-shortest-subarray-with-or-at-least-k-ii
3427-special-array-ii
3429-special-array-i
3434-find-the-number-of-distinct-colors-among-the-balls
3483-alternating-groups-ii
3501-delete-nodes-from-linked-list-present-in-array
3515-find-if-digit-game-can-be-won
3517-shortest-distance-after-road-addition-queries-i
3522-find-the-power-of-k-size-subarrays-i
3621-minimum-operations-to-make-array-values-equal-to-k
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3708-zigzag-grid-traversal-with-skip

Hash Table


0017-letter-combinations-of-a-phone-number
0049-group-anagrams
0073-set-matrix-zeroes
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0126-word-ladder-ii
0127-word-ladder
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0217-contains-duplicate
0229-majority-element-ii
0264-ugly-number-ii
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0355-design-twitter
0432-all-oone-data-structure
0451-sort-characters-by-frequency
0496-next-greater-element-i
0567-permutation-in-string
0621-task-scheduler
0632-smallest-range-covering-elements-from-k-lists
0653-two-sum-iv-input-is-a-bst
0768-partition-labels
0778-reorganize-string
0870-magic-squares-in-grid
0876-hand-of-straights
0893-all-nodes-distance-k-in-binary-tree
0906-walking-robot-simulation
0920-uncommon-words-from-two-sentences
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0952-word-subsets
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1147-flip-columns-for-maximum-number-of-equal-rows
1160-letter-tile-possibilities
1207-delete-nodes-and-return-forest
1256-rank-transform-of-an-array
1364-tuple-with-same-product
1387-find-elements-in-a-contaminated-binary-tree
1422-divide-array-in-sets-of-k-consecutive-numbers
1468-check-if-n-and-its-double-exist
1473-find-the-longest-substring-containing-vowels-in-even-counts
1483-rank-teams-by-votes
1502-construct-k-palindrome-strings
1556-make-two-arrays-equal-by-reversing-subarrays
1620-check-if-array-pairs-are-divisible-by-k
1694-make-sum-divisible-by-p
1715-split-a-string-into-the-max-number-of-unique-substrings
1741-sort-array-by-increasing-frequency
1786-count-the-number-of-consistent-strings
1890-sum-of-beauty-of-all-substrings
1915-check-if-one-string-swap-can-make-strings-equal
1986-largest-color-value-in-a-directed-graph
2054-the-number-of-the-smallest-unoccupied-chair
2059-unique-length-3-palindromic-subsequences
2107-find-unique-binary-string
2163-kth-distinct-string-in-an-array
2215-finding-3-digit-even-numbers
2300-construct-string-with-repeat-limit
2434-design-a-number-container-system
2436-make-array-zero-by-subtracting-equal-amounts
2448-count-number-of-bad-pairs
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2502-sort-the-people
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2552-maximum-sum-of-distinct-subarrays-with-length-k
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2599-take-k-of-each-character-from-left-and-right
2640-maximum-number-of-integers-to-choose-from-a-range-i
2677-cousins-in-binary-tree-ii
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
2755-extra-characters-in-a-string
2766-find-the-prefix-common-array-of-two-arrays
2856-count-complete-subarrays-in-an-array
3227-find-missing-and-repeated-values
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3329-find-the-length-of-the-longest-common-prefix
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
3501-delete-nodes-from-linked-list-present-in-array
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3621-minimum-operations-to-make-array-values-equal-to-k
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

Two Pointers


0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0202-happy-number
0234-palindrome-linked-list
0287-find-the-duplicate-number
0295-find-median-from-data-stream
0350-intersection-of-two-arrays-ii
0455-assign-cookies
0567-permutation-in-string
0653-two-sum-iv-input-is-a-bst
0719-find-k-th-smallest-pair-distance
0768-partition-labels
0908-middle-of-the-linked-list
1468-check-if-n-and-its-double-exist
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1615-range-sum-of-sorted-subarray-sums
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1923-sentence-similarity-iii
1972-rotating-the-box
2095-minimum-number-of-swaps-to-make-the-string-balanced
2216-delete-the-middle-node-of-a-linked-list
2232-adding-spaces-to-a-string
2265-partition-array-according-to-given-pivot
2320-find-all-k-distant-indices-in-an-array
2414-move-pieces-to-obtain-a-string
2488-divide-intervals-into-minimum-number-of-groups
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array
2581-divide-players-into-teams-of-equal-skill
2699-count-the-number-of-fair-pairs
2707-merge-two-2d-arrays-by-summing-values
3018-make-string-a-subsequence-using-cyclic-increments
3195-separate-black-and-white-balls
3683-find-the-lexicographically-largest-string-from-the-box-i

Binary Search


0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0222-count-complete-tree-nodes
0287-find-the-duplicate-number
0350-intersection-of-two-arrays-ii
0540-single-element-in-a-sorted-array
0719-find-k-th-smallest-pair-distance
0729-my-calendar-i
0731-my-calendar-ii
0792-binary-search
0892-shortest-subarray-with-sum-at-least-k
0907-koko-eating-bananas
1056-capacity-to-ship-packages-within-d-days
1335-maximum-candies-allocated-to-k-children
1463-the-k-weakest-rows-in-a-matrix
1468-check-if-n-and-its-double-exist
1605-minimum-number-of-days-to-make-m-bouquets
1615-range-sum-of-sorted-subarray-sums
1646-kth-missing-positive-number
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1753-path-with-minimum-effort
1766-minimum-number-of-removals-to-make-mountain-array
2006-find-the-student-that-will-replace-the-chalk
2150-kth-smallest-product-of-two-sorted-arrays
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2188-minimized-maximum-of-products-distributed-to-any-store
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2665-minimum-time-to-repair-cars
2699-count-the-number-of-fair-pairs
2716-prime-subtraction-operation
2891-maximum-beauty-of-an-array-after-applying-operation
3181-find-building-where-alice-and-bob-can-meet
3267-find-longest-special-substring-that-occurs-thrice-i
3427-special-array-ii

Sorting


0015-3sum
0049-group-anagrams
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0169-majority-element
0179-largest-number
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0350-intersection-of-two-arrays-ii
0451-sort-characters-by-frequency
0455-assign-cookies
0539-minimum-time-difference
0621-task-scheduler
0632-smallest-range-covering-elements-from-k-lists
0719-find-k-th-smallest-pair-distance
0778-reorganize-string
0780-max-chunks-to-make-sorted
0876-hand-of-straights
0883-car-fleet
0948-sort-an-array
1014-k-closest-points-to-origin
1029-vertical-order-traversal-of-a-binary-tree
1256-rank-transform-of-an-array
1333-sort-the-jumbled-numbers
1422-divide-array-in-sets-of-k-consecutive-numbers
1463-the-k-weakest-rows-in-a-matrix
1468-check-if-n-and-its-double-exist
1483-rank-teams-by-votes
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1741-sort-array-by-increasing-frequency
1829-maximum-units-on-a-truck
2164-two-best-non-overlapping-events
2179-most-beautiful-item-for-each-query
2215-finding-3-digit-even-numbers
2387-partition-array-such-that-maximum-difference-is-k
2436-make-array-zero-by-subtracting-equal-amounts
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2488-divide-intervals-into-minimum-number-of-groups
2497-maximum-matching-of-players-with-trainers
2502-sort-the-people
2554-minimum-total-distance-traveled
2581-divide-players-into-teams-of-equal-skill
2586-longest-square-streak-in-an-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
2646-kth-largest-sum-in-a-binary-tree
2695-find-score-of-an-array-after-marking-all-elements
2699-count-the-number-of-fair-pairs
2891-maximum-beauty-of-an-array-after-applying-operation
3219-make-lexicographically-smallest-array-by-swapping-elements
3241-divide-array-into-arrays-with-max-difference
3276-minimum-number-of-pushes-to-type-word-ii
3291-find-if-array-can-be-sorted
3321-type-of-triangle
3360-minimum-deletions-to-make-string-k-special
3647-zero-array-transformation-iii

Tree


0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0257-binary-tree-paths
0404-sum-of-left-leaves
0501-find-mode-in-binary-search-tree
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0530-minimum-absolute-difference-in-bst
0538-convert-bst-to-greater-tree
0543-diameter-of-binary-tree
0563-binary-tree-tilt
0572-subtree-of-another-tree
0606-construct-string-from-binary-tree
0623-add-one-row-to-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0776-n-ary-tree-postorder-traversal
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0893-all-nodes-distance-k-in-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0975-range-sum-of-bst
0988-flip-equivalent-binary-trees
0998-check-completeness-of-a-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal
1093-recover-a-tree-from-preorder-traversal
1116-maximum-level-sum-of-a-binary-tree
1207-delete-nodes-and-return-forest
1387-find-elements-in-a-contaminated-binary-tree
1484-linked-list-in-binary-tree
1653-number-of-good-leaf-nodes-pairs
2384-root-equals-sum-of-children
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2564-most-profitable-path-in-a-tree
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii
3058-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Depth-First Search


0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0129-sum-root-to-leaf-numbers
0130-surrounded-regions
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0257-binary-tree-paths
0386-lexicographical-numbers
0404-sum-of-left-leaves
0501-find-mode-in-binary-search-tree
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0530-minimum-absolute-difference-in-bst
0538-convert-bst-to-greater-tree
0543-diameter-of-binary-tree
0547-number-of-provinces
0563-binary-tree-tilt
0572-subtree-of-another-tree
0606-construct-string-from-binary-tree
0623-add-one-row-to-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0684-redundant-connection
0733-flood-fill
0744-network-delay-time
0776-n-ary-tree-postorder-traversal
0799-minimum-distance-between-bst-nodes
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0854-making-a-large-island
0893-all-nodes-distance-k-in-binary-tree
0975-range-sum-of-bst
0984-most-stones-removed-with-same-row-or-column
0988-flip-equivalent-binary-trees
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1073-number-of-enclaves
1093-recover-a-tree-from-preorder-traversal
1116-maximum-level-sum-of-a-binary-tree
1207-delete-nodes-and-return-forest
1350-remove-sub-folders-from-the-filesystem
1387-find-elements-in-a-contaminated-binary-tree
1442-number-of-operations-to-make-network-connected
1484-linked-list-in-binary-tree
1558-course-schedule-iv
1653-number-of-good-leaf-nodes-pairs
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
2035-count-sub-islands
2201-valid-arrangement-of-pairs
2246-maximum-employees-to-be-invited-to-a-meeting
2438-find-closest-node-to-given-two-nodes
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2564-most-profitable-path-in-a-tree
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid
3058-maximum-number-of-k-divisible-components
3439-find-minimum-diameter-after-merging-two-trees
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Binary Tree


0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0257-binary-tree-paths
0404-sum-of-left-leaves
0501-find-mode-in-binary-search-tree
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0530-minimum-absolute-difference-in-bst
0538-convert-bst-to-greater-tree
0543-diameter-of-binary-tree
0563-binary-tree-tilt
0572-subtree-of-another-tree
0606-construct-string-from-binary-tree
0623-add-one-row-to-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0893-all-nodes-distance-k-in-binary-tree
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0975-range-sum-of-bst
0988-flip-equivalent-binary-trees
0998-check-completeness-of-a-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal
1093-recover-a-tree-from-preorder-traversal
1116-maximum-level-sum-of-a-binary-tree
1207-delete-nodes-and-return-forest
1387-find-elements-in-a-contaminated-binary-tree
1484-linked-list-in-binary-tree
1653-number-of-good-leaf-nodes-pairs
2384-root-equals-sum-of-children
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii

Linked List


0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0061-rotate-list
0083-remove-duplicates-from-sorted-list
0114-flatten-binary-tree-to-linked-list
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0146-lru-cache
0148-sort-list
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0328-odd-even-linked-list
0355-design-twitter
0382-linked-list-random-node
0432-all-oone-data-structure
0725-split-linked-list-in-parts
0859-design-circular-deque
0908-middle-of-the-linked-list
1484-linked-list-in-binary-tree
2216-delete-the-middle-node-of-a-linked-list
2411-spiral-matrix-iv
2903-insert-greatest-common-divisors-in-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Recursion


0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0050-powx-n
0143-reorder-list
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0241-different-ways-to-add-parentheses
0273-integer-to-english-words
1197-parsing-a-boolean-expression
1667-find-kth-bit-in-nth-binary-string
2050-count-good-numbers

Divide and Conquer


0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0948-sort-an-array
1014-k-closest-points-to-origin

Counting


0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0621-task-scheduler
0778-reorganize-string
0920-uncommon-words-from-two-sentences
1160-letter-tile-possibilities
1364-tuple-with-same-product
1483-rank-teams-by-votes
1502-construct-k-palindrome-strings
1620-check-if-array-pairs-are-divisible-by-k
1708-design-parking-system
1786-count-the-number-of-consistent-strings
1890-sum-of-beauty-of-all-substrings
1915-check-if-one-string-swap-can-make-strings-equal
1986-largest-color-value-in-a-directed-graph
2163-kth-distinct-string-in-an-array
2300-construct-string-with-repeat-limit
2448-count-number-of-bad-pairs
2494-sum-of-prefix-scores-of-strings
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3360-minimum-deletions-to-make-string-k-special
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes

Matrix


0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0079-word-search
0130-surrounded-regions
0407-trapping-rain-water-ii
0542-01-matrix
0733-flood-fill
0787-sliding-puzzle
0854-making-a-large-island
0870-magic-squares-in-grid
0921-spiral-matrix-iii
0945-snakes-and-ladders
0999-regions-cut-by-slashes
1036-rotting-oranges
1073-number-of-enclaves
1147-flip-columns-for-maximum-number-of-equal-rows
1171-shortest-path-in-binary-matrix
1402-count-square-submatrices-with-all-ones
1463-the-k-weakest-rows-in-a-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1496-lucky-numbers-in-a-matrix
1691-minimum-number-of-days-to-disconnect-island
1711-find-valid-matrix-given-row-and-column-sums
1753-path-with-minimum-effort
1876-map-of-highest-peak
1972-rotating-the-box
2035-count-sub-islands
2089-maximum-matrix-sum
2132-convert-1d-array-into-2d-array
2145-grid-game
2343-count-unguarded-cells-in-the-grid
2375-minimum-obstacle-removal-to-reach-corner
2411-spiral-matrix-iv
2472-build-a-matrix-with-conditions
2685-first-completely-painted-row-or-column
2764-maximum-number-of-fish-in-a-grid
2794-maximum-number-of-moves-in-a-grid
3227-find-missing-and-repeated-values
3708-zigzag-grid-traversal-with-skip

Greedy


0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0135-candy
0179-largest-number
0455-assign-cookies
0621-task-scheduler
0624-maximum-distance-in-arrays
0632-smallest-range-covering-elements-from-k-lists
0670-maximum-swap
0678-valid-parenthesis-string
0768-partition-labels
0778-reorganize-string
0780-max-chunks-to-make-sorted
0876-hand-of-straights
0890-lemonade-change
0957-minimum-add-to-make-parentheses-valid
1304-longest-happy-string
1422-divide-array-in-sets-of-k-consecutive-numbers
1502-construct-k-palindrome-strings
1529-max-difference-you-can-get-from-changing-an-integer
1711-find-valid-matrix-given-row-and-column-sums
1766-minimum-number-of-removals-to-make-mountain-array
1829-maximum-units-on-a-truck
1917-maximum-average-pass-ratio
2089-maximum-matrix-sum
2095-minimum-number-of-swaps-to-make-the-string-balanced
2221-check-if-a-parentheses-string-can-be-valid
2300-construct-string-with-repeat-limit
2387-partition-array-such-that-maximum-difference-is-k
2436-make-array-zero-by-subtracting-equal-amounts
2456-construct-smallest-number-from-di-string
2488-divide-intervals-into-minimum-number-of-groups
2497-maximum-matching-of-players-with-trainers
2509-minimize-xor
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2616-maximal-score-after-applying-k-operations
2640-maximum-number-of-integers-to-choose-from-a-range-i
2704-maximum-difference-by-remapping-a-digit
2716-prime-subtraction-operation
3143-longest-unequal-adjacent-groups-subsequence-i
3171-minimum-equal-sum-of-two-arrays-after-replacing-zeros
3195-separate-black-and-white-balls
3241-divide-array-into-arrays-with-max-difference
3276-minimum-number-of-pushes-to-type-word-ii
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii

Stack


0020-valid-parentheses
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0150-evaluate-reverse-polish-notation
0155-min-stack
0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0496-next-greater-element-i
0503-next-greater-element-ii
0678-valid-parenthesis-string
0735-asteroid-collision
0739-daily-temperatures
0776-n-ary-tree-postorder-traversal
0780-max-chunks-to-make-sorted
0883-car-fleet
0957-minimum-add-to-make-parentheses-valid
1002-maximum-width-ramp
1050-construct-binary-search-tree-from-preorder-traversal
1078-remove-outermost-parentheses
1197-parsing-a-boolean-expression
1497-design-a-stack-with-increment-operation
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
1756-minimum-deletions-to-make-string-balanced
2021-remove-all-occurrences-of-a-substring
2095-minimum-number-of-swaps-to-make-the-string-balanced
2221-check-if-a-parentheses-string-can-be-valid
2227-sum-of-subarray-ranges
2456-construct-smallest-number-from-di-string
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2800-minimum-string-length-after-removing-substrings
3181-find-building-where-alice-and-bob-can-meet
3445-lexicographically-minimum-string-after-removing-stars

Graph


0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0684-redundant-connection
0744-network-delay-time
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0984-most-stones-removed-with-same-row-or-column
1325-path-with-maximum-probability
1424-maximum-candies-you-can-get-from-boxes
1442-number-of-operations-to-make-network-connected
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2171-second-minimum-time-to-reach-destination
2201-valid-arrangement-of-pairs
2246-maximum-employees-to-be-invited-to-a-meeting
2375-minimum-obstacle-removal-to-reach-corner
2438-find-closest-node-to-given-two-nodes
2472-build-a-matrix-with-conditions
2564-most-profitable-path-in-a-tree
2583-divide-nodes-into-the-maximum-number-of-groups
2803-modify-graph-edge-weights
3189-find-champion-ii
3235-minimum-cost-to-convert-string-i
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i

Topological Sort


0207-course-schedule
0210-course-schedule-ii
0820-find-eventual-safe-states
1558-course-schedule-iv
1986-largest-color-value-in-a-directed-graph
2090-number-of-ways-to-arrive-at-destination
2246-maximum-employees-to-be-invited-to-a-meeting
2472-build-a-matrix-with-conditions

String


0005-longest-palindromic-substring
0008-string-to-integer-atoi
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0079-word-search
0126-word-ladder-ii
0127-word-ladder
0131-palindrome-partitioning
0151-reverse-words-in-a-string
0179-largest-number
0214-shortest-palindrome
0241-different-ways-to-add-parentheses
0257-binary-tree-paths
0273-integer-to-english-words
0451-sort-characters-by-frequency
0539-minimum-time-difference
0564-find-the-closest-palindrome
0567-permutation-in-string
0592-fraction-addition-and-subtraction
0606-construct-string-from-binary-tree
0664-strange-printer
0678-valid-parenthesis-string
0768-partition-labels
0778-reorganize-string
0812-rotate-string
0920-uncommon-words-from-two-sentences
0952-word-subsets
0957-minimum-add-to-make-parentheses-valid
1058-lexicographically-smallest-equivalent-string
1078-remove-outermost-parentheses
1093-recover-a-tree-from-preorder-traversal
1160-letter-tile-possibilities
1197-parsing-a-boolean-expression
1250-longest-common-subsequence
1302-delete-characters-to-make-fancy-string
1304-longest-happy-string
1350-remove-sub-folders-from-the-filesystem
1473-find-the-longest-substring-containing-vowels-in-even-counts
1483-rank-teams-by-votes
1502-construct-k-palindrome-strings
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1524-string-matching-in-an-array
1537-maximum-score-after-splitting-a-string
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
1667-find-kth-bit-in-nth-binary-string
1715-split-a-string-into-the-max-number-of-unique-substrings
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1756-minimum-deletions-to-make-string-balanced
1786-count-the-number-of-consistent-strings
1890-sum-of-beauty-of-all-substrings
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1915-check-if-one-string-swap-can-make-strings-equal
1923-sentence-similarity-iii
2021-remove-all-occurrences-of-a-substring
2059-unique-length-3-palindromic-subsequences
2076-sum-of-digits-of-string-after-convert
2095-minimum-number-of-swaps-to-make-the-string-balanced
2107-find-unique-binary-string
2163-kth-distinct-string-in-an-array
2173-number-of-valid-words-in-a-sentence
2221-check-if-a-parentheses-string-can-be-valid
2232-adding-spaces-to-a-string
2260-divide-a-string-into-groups-of-size-k
2292-counting-words-with-a-given-prefix
2300-construct-string-with-repeat-limit
2414-move-pieces-to-obtain-a-string
2456-construct-smallest-number-from-di-string
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2494-sum-of-prefix-scores-of-strings
2502-sort-the-people
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2580-circular-sentence
2599-take-k-of-each-character-from-left-and-right
2691-count-vowel-strings-in-ranges
2727-number-of-senior-citizens
2755-extra-characters-in-a-string
2800-minimum-string-length-after-removing-substrings
3018-make-string-a-subsequence-using-cyclic-increments
3143-longest-unequal-adjacent-groups-subsequence-i
3174-minimum-number-of-changes-to-make-binary-string-beautiful
3194-find-words-containing-character
3195-separate-black-and-white-balls
3235-minimum-cost-to-convert-string-i
3267-find-longest-special-substring-that-occurs-thrice-i
3276-minimum-number-of-pushes-to-type-word-ii
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars
3451-string-compression-iii
3553-check-if-two-chessboard-squares-have-the-same-color
3567-convert-date-to-binary
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3683-find-the-lexicographically-largest-string-from-the-box-i
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

Merge Sort


0023-merge-k-sorted-lists
0148-sort-list
0948-sort-an-array

Heap (Priority Queue)


0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0264-ugly-number-ii
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0355-design-twitter
0407-trapping-rain-water-ii
0451-sort-characters-by-frequency
0621-task-scheduler
0632-smallest-range-covering-elements-from-k-lists
0744-network-delay-time
0778-reorganize-string
0789-kth-largest-element-in-a-stream
0803-cheapest-flights-within-k-stops
0892-shortest-subarray-with-sum-at-least-k
0948-sort-an-array
1014-k-closest-points-to-origin
1127-last-stone-weight
1304-longest-happy-string
1325-path-with-maximum-probability
1463-the-k-weakest-rows-in-a-matrix
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1753-path-with-minimum-effort
1917-maximum-average-pass-ratio
2054-the-number-of-the-smallest-unoccupied-chair
2164-two-best-non-overlapping-events
2300-construct-string-with-repeat-limit
2375-minimum-obstacle-removal-to-reach-corner
2434-design-a-number-container-system
2436-make-array-zero-by-subtracting-equal-amounts
2473-max-sum-of-a-pair-with-equal-sum-of-digits
2488-divide-intervals-into-minimum-number-of-groups
2616-maximal-score-after-applying-k-operations
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2803-modify-graph-edge-weights
2868-continuous-subarrays
3181-find-building-where-alice-and-bob-can-meet
3445-lexicographically-minimum-string-after-removing-stars
3647-zero-array-transformation-iii

Bucket Sort


0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0948-sort-an-array

Radix Sort


0948-sort-an-array

Counting Sort


0948-sort-an-array

Dynamic Programming


0005-longest-palindromic-substring
0022-generate-parentheses
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0131-palindrome-partitioning
0152-maximum-product-subarray
0198-house-robber
0213-house-robber-ii
0241-different-ways-to-add-parentheses
0264-ugly-number-ii
0494-target-sum
0542-01-matrix
0650-2-keys-keyboard
0664-strange-printer
0678-valid-parenthesis-string
0803-cheapest-flights-within-k-stops
0909-stone-game
1025-minimum-cost-for-tickets
1063-best-sightseeing-pair
1196-filling-bookcase-shelves
1240-stone-game-ii
1250-longest-common-subsequence
1402-count-square-submatrices-with-all-ones
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1511-count-number-of-teams
1631-number-of-sub-arrays-with-odd-sum
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1756-minimum-deletions-to-make-string-balanced
1766-minimum-number-of-removals-to-make-mountain-array
1986-largest-color-value-in-a-directed-graph
2067-maximum-number-of-points-with-cost
2090-number-of-ways-to-arrive-at-destination
2164-two-best-non-overlapping-events
2554-minimum-total-distance-traveled
2562-count-ways-to-build-good-strings
2586-longest-square-streak-in-an-array
2755-extra-characters-in-a-string
2794-maximum-number-of-moves-in-a-grid
3143-longest-unequal-adjacent-groups-subsequence-i

Shortest Path


0744-network-delay-time
0803-cheapest-flights-within-k-stops
1325-path-with-maximum-probability
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
2090-number-of-ways-to-arrive-at-destination
2171-second-minimum-time-to-reach-destination
2375-minimum-obstacle-removal-to-reach-corner
2803-modify-graph-edge-weights
3235-minimum-cost-to-convert-string-i

Breadth-First Search


0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0126-word-ladder-ii
0127-word-ladder
0130-surrounded-regions
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0404-sum-of-left-leaves
0407-trapping-rain-water-ii
0513-find-bottom-left-tree-value
0515-find-largest-value-in-each-tree-row
0530-minimum-absolute-difference-in-bst
0542-01-matrix
0547-number-of-provinces
0623-add-one-row-to-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0684-redundant-connection
0733-flood-fill
0744-network-delay-time
0787-sliding-puzzle
0799-minimum-distance-between-bst-nodes
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0854-making-a-large-island
0893-all-nodes-distance-k-in-binary-tree
0945-snakes-and-ladders
0998-check-completeness-of-a-binary-tree
0999-regions-cut-by-slashes
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1073-number-of-enclaves
1116-maximum-level-sum-of-a-binary-tree
1171-shortest-path-in-binary-matrix
1387-find-elements-in-a-contaminated-binary-tree
1424-maximum-candies-you-can-get-from-boxes
1442-number-of-operations-to-make-network-connected
1484-linked-list-in-binary-tree
1485-minimum-cost-to-make-at-least-one-valid-path-in-a-grid
1558-course-schedule-iv
1691-minimum-number-of-days-to-disconnect-island
1753-path-with-minimum-effort
1876-map-of-highest-peak
2035-count-sub-islands
2171-second-minimum-time-to-reach-destination
2375-minimum-obstacle-removal-to-reach-corner
2493-reverse-odd-levels-of-binary-tree
2545-height-of-binary-tree-after-subtree-removal-queries
2558-minimum-number-of-operations-to-sort-a-binary-tree-by-level
2564-most-profitable-path-in-a-tree
2583-divide-nodes-into-the-maximum-number-of-groups
2646-kth-largest-sum-in-a-binary-tree
2677-cousins-in-binary-tree-ii
2764-maximum-number-of-fish-in-a-grid
3439-find-minimum-diameter-after-merging-two-trees
3517-shortest-distance-after-road-addition-queries-i
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i

Binary Indexed Tree


1511-count-number-of-teams
3181-find-building-where-alice-and-bob-can-meet

Sliding Window


0239-sliding-window-maximum
0567-permutation-in-string
0632-smallest-range-covering-elements-from-k-lists
0892-shortest-subarray-with-sum-at-least-k
1755-defuse-the-bomb
2255-minimum-swaps-to-group-all-1s-together-ii
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2552-maximum-sum-of-distinct-subarrays-with-length-k
2599-take-k-of-each-character-from-left-and-right
2856-count-complete-subarrays-in-an-array
2868-continuous-subarrays
2891-maximum-beauty-of-an-array-after-applying-operation
3267-find-longest-special-substring-that-occurs-thrice-i
3380-shortest-subarray-with-or-at-least-k-ii
3483-alternating-groups-ii
3522-find-the-power-of-k-size-subarrays-i
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3761-maximum-difference-between-even-and-odd-frequency-ii

Math


0007-reverse-integer
0009-palindrome-number
0029-divide-two-integers
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0202-happy-number
0204-count-primes
0231-power-of-two
0241-different-ways-to-add-parentheses
0263-ugly-number
0264-ugly-number-ii
0273-integer-to-english-words
0382-linked-list-random-node
0539-minimum-time-difference
0564-find-the-closest-palindrome
0592-fraction-addition-and-subtraction
0650-2-keys-keyboard
0670-maximum-swap
0870-magic-squares-in-grid
0909-stone-game
1014-k-closest-points-to-origin
1240-stone-game-ii
1477-product-of-the-last-k-numbers
1529-max-difference-you-can-get-from-changing-an-integer
1585-the-kth-factor-of-n
1630-count-odd-numbers-in-an-interval-range
1631-number-of-sub-arrays-with-odd-sum
1889-check-if-number-is-a-sum-of-powers-of-three
1993-sum-of-all-subset-xor-totals
2050-count-good-numbers
2106-find-greatest-common-divisor-of-array
2155-find-missing-observations
2324-find-triangular-sum-of-an-array
2448-count-number-of-bad-pairs
2507-number-of-common-factors
2610-closest-prime-numbers-in-range
2704-maximum-difference-by-remapping-a-digit
2716-prime-subtraction-operation
2802-find-the-punishment-number-of-an-integer
2903-insert-greatest-common-divisors-in-linked-list
3172-divisible-and-non-divisible-sums-difference
3199-distribute-candies-among-children-i
3201-distribute-candies-among-children-ii
3227-find-missing-and-repeated-values
3321-type-of-triangle
3515-find-if-digit-game-can-be-won
3553-check-if-two-chessboard-squares-have-the-same-color
3567-convert-date-to-binary
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements
3754-maximum-manhattan-distance-after-k-changes

Bit Manipulation


0029-divide-two-integers
0067-add-binary
0078-subsets
0090-subsets-ii
0222-count-complete-tree-nodes
0231-power-of-two
0287-find-the-duplicate-number
0476-number-complement
1054-complement-of-base-10-integer
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1786-count-the-number-of-consistent-strings
1940-maximum-xor-for-each-query
1993-sum-of-all-subset-xor-totals
2059-unique-length-3-palindromic-subsequences
2170-count-number-of-maximum-bitwise-or-subsets
2323-minimum-bit-flips-to-convert-number
2503-longest-subarray-with-maximum-bitwise-and
2509-minimize-xor
2533-bitwise-xor-of-all-pairings
2766-find-the-prefix-common-array-of-two-arrays
2792-neighboring-bitwise-xor
3291-find-if-array-can-be-sorted
3380-shortest-subarray-with-or-at-least-k-ii
3394-minimum-array-end

Simulation


0054-spiral-matrix
0067-add-binary
0592-fraction-addition-and-subtraction
0735-asteroid-collision
0906-walking-robot-simulation
0921-spiral-matrix-iii
1667-find-kth-bit-in-nth-binary-string
1708-design-parking-system
2006-find-the-student-that-will-replace-the-chalk
2021-remove-all-occurrences-of-a-substring
2076-sum-of-digits-of-string-after-convert
2132-convert-1d-array-into-2d-array
2155-find-missing-observations
2232-adding-spaces-to-a-string
2260-divide-a-string-into-groups-of-size-k
2265-partition-array-according-to-given-pivot
2324-find-triangular-sum-of-an-array
2343-count-unguarded-cells-in-the-grid
2411-spiral-matrix-iv
2436-make-array-zero-by-subtracting-equal-amounts
2551-apply-operations-to-an-array
2692-take-gifts-from-the-richest-pile
2695-find-score-of-an-array-after-marking-all-elements
2800-minimum-string-length-after-removing-substrings
3434-find-the-number-of-distinct-colors-among-the-balls
3708-zigzag-grid-traversal-with-skip

Design


0146-lru-cache
0155-min-stack
0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0355-design-twitter
0432-all-oone-data-structure
0729-my-calendar-i
0731-my-calendar-ii
0789-kth-largest-element-in-a-stream
0859-design-circular-deque
1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
1497-design-a-stack-with-increment-operation
1708-design-parking-system
2434-design-a-number-container-system

Queue


0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
0859-design-circular-deque
0892-shortest-subarray-with-sum-at-least-k
2868-continuous-subarrays

Union Find


0130-surrounded-regions
0547-number-of-provinces
0684-redundant-connection
0801-is-graph-bipartite
0854-making-a-large-island
0984-most-stones-removed-with-same-row-or-column
0999-regions-cut-by-slashes
1058-lexicographically-smallest-equivalent-string
1073-number-of-enclaves
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
2035-count-sub-islands
2583-divide-nodes-into-the-maximum-number-of-groups
2764-maximum-number-of-fish-in-a-grid
3219-make-lexicographically-smallest-array-by-swapping-elements

Strongly Connected Component


1691-minimum-number-of-days-to-disconnect-island

Binary Search Tree


0098-validate-binary-search-tree
0099-recover-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0501-find-mode-in-binary-search-tree
0530-minimum-absolute-difference-in-bst
0538-convert-bst-to-greater-tree
0653-two-sum-iv-input-is-a-bst
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0799-minimum-distance-between-bst-nodes
0975-range-sum-of-bst
1050-construct-binary-search-tree-from-preorder-traversal

Data Stream


0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream
1477-product-of-the-last-k-numbers

Backtracking


0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0078-subsets
0079-word-search
0090-subsets-ii
0126-word-ladder-ii
0131-palindrome-partitioning
0257-binary-tree-paths
0494-target-sum
1160-letter-tile-possibilities
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1715-split-a-string-into-the-max-number-of-unique-substrings
1819-construct-the-lexicographically-largest-valid-sequence
1993-sum-of-all-subset-xor-totals
2107-find-unique-binary-string
2170-count-number-of-maximum-bitwise-or-subsets
2456-construct-smallest-number-from-di-string
2802-find-the-punishment-number-of-an-integer

Monotonic Stack


0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
0780-max-chunks-to-make-sorted
0883-car-fleet
1002-maximum-width-ramp
1050-construct-binary-search-tree-from-preorder-traversal
1570-final-prices-with-a-special-discount-in-a-shop
1679-shortest-subarray-to-be-removed-to-make-array-sorted
2227-sum-of-subarray-ranges
3181-find-building-where-alice-and-bob-can-meet

Prefix Sum


0238-product-of-array-except-self
0724-find-pivot-index
0731-my-calendar-ii
0892-shortest-subarray-with-sum-at-least-k
1240-stone-game-ii
1435-xor-queries-of-a-subarray
1473-find-the-longest-substring-containing-vowels-in-even-counts
1477-product-of-the-last-k-numbers
1537-maximum-score-after-splitting-a-string
1631-number-of-sub-arrays-with-odd-sum
1694-make-sum-divisible-by-p
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1940-maximum-xor-for-each-query
2006-find-the-student-that-will-replace-the-chalk
2059-unique-length-3-palindromic-subsequences
2102-find-the-middle-index-in-array
2145-grid-game
2358-number-of-ways-to-split-array
2465-shifting-letters-ii
2488-divide-intervals-into-minimum-number-of-groups
2691-count-vowel-strings-in-ranges
3427-special-array-ii
3639-zero-array-transformation-i
3647-zero-array-transformation-iii
3761-maximum-difference-between-even-and-odd-frequency-ii

Game Theory


0909-stone-game
1240-stone-game-ii

Enumeration


0204-count-primes
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2215-finding-3-digit-even-numbers
2507-number-of-common-factors
3199-distribute-candies-among-children-i
3201-distribute-candies-among-children-ii
3683-find-the-lexicographically-largest-string-from-the-box-i
3761-maximum-difference-between-even-and-odd-frequency-ii

Number Theory


0204-count-primes
1585-the-kth-factor-of-n
2106-find-greatest-common-divisor-of-array
2507-number-of-common-factors
2610-closest-prime-numbers-in-range
2716-prime-subtraction-operation
2903-insert-greatest-common-divisors-in-linked-list

Database


0175-combine-two-tables
0181-employees-earning-more-than-their-managers
0182-duplicate-emails

Quickselect


0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

String Matching


0028-find-the-index-of-the-first-occurrence-in-a-string
0214-shortest-palindrome
0572-subtree-of-another-tree
0812-rotate-string
1524-string-matching-in-an-array
1566-check-if-a-word-occurs-as-a-prefix-of-any-word-in-a-sentence
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Hash Function


0214-shortest-palindrome
0572-subtree-of-another-tree
3309-count-prefix-and-suffix-pairs-i

Brainteaser


2503-longest-subarray-with-maximum-bitwise-and
2533-bitwise-xor-of-all-pairings

Memoization


0070-climbing-stairs
0241-different-ways-to-add-parentheses
1986-largest-color-value-in-a-directed-graph

Rolling Hash


0214-shortest-palindrome
3309-count-prefix-and-suffix-pairs-i

Combinatorics


0062-unique-paths
1993-sum-of-all-subset-xor-totals
2324-find-triangular-sum-of-an-array
3199-distribute-candies-among-children-i
3201-distribute-candies-among-children-ii
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements

Iterator


0173-binary-search-tree-iterator

Trie


0014-longest-common-prefix
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
1350-remove-sub-folders-from-the-filesystem
2494-sum-of-prefix-scores-of-strings
2755-extra-characters-in-a-string
3309-count-prefix-and-suffix-pairs-i
3329-find-the-length-of-the-longest-common-prefix

Segment Tree


0729-my-calendar-i
0731-my-calendar-ii
3181-find-building-where-alice-and-bob-can-meet

Ordered Set


0729-my-calendar-i
0731-my-calendar-ii
2434-design-a-number-container-system
2868-continuous-subarrays

Doubly-Linked List


0146-lru-cache
0432-all-oone-data-structure

Monotonic Queue


0239-sliding-window-maximum
0892-shortest-subarray-with-sum-at-least-k
2868-continuous-subarrays

Eulerian Circuit


2201-valid-arrangement-of-pairs

Reservoir Sampling


0382-linked-list-random-node

Randomized


0382-linked-list-random-node

Geometry


1014-k-closest-points-to-origin

Name		Name	Last commit message	Last commit date
Latest commit History 2,395 Commits
0005-longest-palindromic-substring		0005-longest-palindromic-substring
0007-reverse-integer		0007-reverse-integer
0008-string-to-integer-atoi		0008-string-to-integer-atoi
0009-palindrome-number		0009-palindrome-number
0011-container-with-most-water		0011-container-with-most-water
0014-longest-common-prefix		0014-longest-common-prefix
0015-3sum		0015-3sum
0017-letter-combinations-of-a-phone-number		0017-letter-combinations-of-a-phone-number
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
0022-generate-parentheses		0022-generate-parentheses
0023-merge-k-sorted-lists		0023-merge-k-sorted-lists
0024-swap-nodes-in-pairs		0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group		0025-reverse-nodes-in-k-group
0026-remove-duplicates-from-sorted-array		0026-remove-duplicates-from-sorted-array
0027-remove-element		0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string		0028-find-the-index-of-the-first-occurrence-in-a-string
0029-divide-two-integers		0029-divide-two-integers
0031-next-permutation		0031-next-permutation
0033-search-in-rotated-sorted-array		0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array		0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position		0035-search-insert-position
0036-valid-sudoku		0036-valid-sudoku
0039-combination-sum		0039-combination-sum
0040-combination-sum-ii		0040-combination-sum-ii
0045-jump-game-ii		0045-jump-game-ii
0046-permutations		0046-permutations
0048-rotate-image		0048-rotate-image
0049-group-anagrams		0049-group-anagrams
0050-powx-n		0050-powx-n
0051-n-queens		0051-n-queens
0053-maximum-subarray		0053-maximum-subarray
0054-spiral-matrix		0054-spiral-matrix
0055-jump-game		0055-jump-game
0058-length-of-last-word		0058-length-of-last-word
0061-rotate-list		0061-rotate-list
0062-unique-paths		0062-unique-paths
0066-plus-one		0066-plus-one
0067-add-binary		0067-add-binary
0069-sqrtx		0069-sqrtx
0070-climbing-stairs		0070-climbing-stairs
0073-set-matrix-zeroes		0073-set-matrix-zeroes
0075-sort-colors		0075-sort-colors
0078-subsets		0078-subsets
0079-word-search		0079-word-search
0081-search-in-rotated-sorted-array-ii		0081-search-in-rotated-sorted-array-ii
0083-remove-duplicates-from-sorted-list		0083-remove-duplicates-from-sorted-list
0088-merge-sorted-array		0088-merge-sorted-array
0090-subsets-ii		0090-subsets-ii
0094-binary-tree-inorder-traversal		0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree		0098-validate-binary-search-tree
0099-recover-binary-search-tree		0099-recover-binary-search-tree
0100-same-tree		0100-same-tree
0101-symmetric-tree		0101-symmetric-tree
0102-binary-tree-level-order-traversal		0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal		0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree		0104-maximum-depth-of-binary-tree
0105-construct-binary-tree-from-preorder-and-inorder-traversal		0105-construct-binary-tree-from-preorder-and-inorder-traversal
0110-balanced-binary-tree		0110-balanced-binary-tree
0111-minimum-depth-of-binary-tree		0111-minimum-depth-of-binary-tree
0112-path-sum		0112-path-sum
0114-flatten-binary-tree-to-linked-list		0114-flatten-binary-tree-to-linked-list
0118-pascals-triangle		0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock		0121-best-time-to-buy-and-sell-stock
0126-word-ladder-ii		0126-word-ladder-ii
0127-word-ladder		0127-word-ladder
0129-sum-root-to-leaf-numbers		0129-sum-root-to-leaf-numbers
0130-surrounded-regions		0130-surrounded-regions
0131-palindrome-partitioning		0131-palindrome-partitioning
0135-candy		0135-candy
0138-copy-list-with-random-pointer		0138-copy-list-with-random-pointer
0141-linked-list-cycle		0141-linked-list-cycle
0142-linked-list-cycle-ii		0142-linked-list-cycle-ii
0143-reorder-list		0143-reorder-list
0144-binary-tree-preorder-traversal		0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal		0145-binary-tree-postorder-traversal
0146-lru-cache		0146-lru-cache
0148-sort-list		0148-sort-list
0150-evaluate-reverse-polish-notation		0150-evaluate-reverse-polish-notation
0151-reverse-words-in-a-string		0151-reverse-words-in-a-string
0152-maximum-product-subarray		0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array		0153-find-minimum-in-rotated-sorted-array
0155-min-stack		0155-min-stack
0160-intersection-of-two-linked-lists		0160-intersection-of-two-linked-lists
0162-find-peak-element		0162-find-peak-element
0169-majority-element		0169-majority-element
0173-binary-search-tree-iterator		0173-binary-search-tree-iterator
0175-combine-two-tables		0175-combine-two-tables
0179-largest-number		0179-largest-number
0181-employees-earning-more-than-their-managers		0181-employees-earning-more-than-their-managers
0182-duplicate-emails		0182-duplicate-emails
0198-house-robber		0198-house-robber
0199-binary-tree-right-side-view		0199-binary-tree-right-side-view
0202-happy-number		0202-happy-number
0204-count-primes		0204-count-primes
0206-reverse-linked-list		0206-reverse-linked-list
0207-course-schedule		0207-course-schedule
0210-course-schedule-ii		0210-course-schedule-ii
0213-house-robber-ii		0213-house-robber-ii

yugalgaur174/Leetcode-Problems

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Leetcode-problem

LeetCode Topics

Array

Hash Table

Two Pointers

Binary Search

Sorting

Tree

Depth-First Search

Binary Tree

Linked List

Recursion

Divide and Conquer

Counting

Matrix

Greedy

Stack

Graph

Topological Sort

String

Merge Sort

Heap (Priority Queue)

Bucket Sort

Radix Sort

Counting Sort

Dynamic Programming

Shortest Path

Breadth-First Search

Binary Indexed Tree

Sliding Window

Math

Bit Manipulation

Simulation

Design

Queue

Union Find

Strongly Connected Component

Binary Search Tree

Data Stream

Backtracking

Monotonic Stack

Prefix Sum

Game Theory

Enumeration

Number Theory

Database

Quickselect

String Matching

Hash Function

Brainteaser

Memoization

Rolling Hash

Combinatorics

Iterator

Trie

Segment Tree

Ordered Set

Doubly-Linked List

Monotonic Queue

Eulerian Circuit

Reservoir Sampling

Randomized

Geometry

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