Collection of LeetCode questions to ace the coding interview! - Created using LeetHub

LeetCode Topics

Array

0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
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
0036-valid-sudoku
0046-permutations
0047-permutations-ii
0048-rotate-image
0053-maximum-subarray
0063-unique-paths-ii
0066-plus-one
0074-search-a-2d-matrix
0078-subsets
0079-word-search
0080-remove-duplicates-from-sorted-array-ii
0118-pascals-triangle
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0135-candy
0139-word-break
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0219-contains-duplicate-ii
0229-majority-element-ii
0240-search-a-2d-matrix-ii
0260-single-number-iii
0268-missing-number
0283-move-zeroes
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0324-wiggle-sort-ii
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0435-non-overlapping-intervals
0436-find-right-interval
0442-find-all-duplicates-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0452-minimum-number-of-arrows-to-burst-balloons
0454-4sum-ii
0456-132-pattern
0474-ones-and-zeroes
0485-max-consecutive-ones
0491-non-decreasing-subsequences
0496-next-greater-element-i
0498-diagonal-traverse
0518-coin-change-ii
0532-k-diff-pairs-in-an-array
0575-distribute-candies
0594-longest-harmonious-subsequence
0605-can-place-flowers
0611-valid-triangle-number
0679-24-game
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0739-daily-temperatures
0745-find-smallest-letter-greater-than-target
0757-set-intersection-size-at-least-two
0792-binary-search
0808-number-of-matching-subsequences
0853-most-profit-assigning-work
0912-random-pick-with-weight
0932-monotonic-array
0945-snakes-and-ladders
0966-binary-subarrays-with-sum
1006-vowel-spellchecker
1022-unique-paths-iii
1041-available-captures-for-rook
1046-max-consecutive-ones-iii
1055-pairs-of-songs-with-total-durations-divisible-by-60
1217-relative-sort-array
1256-rank-transform-of-an-array
1305-number-of-visible-people-in-a-queue
1306-minimum-absolute-difference
1350-remove-sub-folders-from-the-filesystem
1353-find-resultant-array-after-removing-anagrams
1402-count-square-submatrices-with-all-ones
1418-fair-distribution-of-cookies
1424-maximum-candies-you-can-get-from-boxes
1426-find-n-unique-integers-sum-up-to-zero
1476-count-negative-numbers-in-a-sorted-matrix
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1519-minimum-subsequence-in-non-increasing-order
1586-longest-subarray-of-1s-after-deleting-one-element
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1669-minimum-cost-to-cut-a-stick
1675-magnetic-force-between-two-balls
1723-maximum-number-of-achievable-transfer-requests
1813-maximum-erasure-value
1834-minimum-number-of-people-to-teach
1851-maximum-number-of-events-that-can-be-attended-ii
1917-maximum-average-pass-ratio
1995-finding-pairs-with-a-certain-sum
2000-minimum-speed-to-arrive-on-time
2122-count-special-quadruplets
2137-final-value-of-variable-after-performing-operations
2144-maximum-difference-between-increasing-elements
2150-kth-smallest-product-of-two-sorted-arrays
2165-plates-between-candles
2169-simple-bank-system
2170-count-number-of-maximum-bitwise-or-subsets
2204-find-subsequence-of-length-k-with-the-largest-sum
2229-maximum-fruits-harvested-after-at-most-k-steps
2237-longest-palindrome-by-concatenating-two-letter-words
2240-intervals-between-identical-elements
2248-minimum-cost-of-buying-candies-with-discount
2254-check-if-every-row-and-column-contains-all-numbers
2269-count-elements-with-strictly-smaller-and-greater-elements
2271-rearrange-array-elements-by-sign
2294-minimum-time-to-complete-trips
2307-replace-non-coprime-numbers-in-array
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2324-find-triangular-sum-of-an-array
2343-count-unguarded-cells-in-the-grid
2387-partition-array-such-that-maximum-difference-is-k
2392-successful-pairs-of-spells-and-potions
2400-minimum-score-after-removals-on-a-tree
2432-number-of-zero-filled-subarrays
2469-longest-subsequence-with-limited-sum
2478-longest-nice-subarray
2497-maximum-matching-of-players-with-trainers
2498-smallest-subarrays-with-maximum-bitwise-or
2529-range-product-queries-of-powers
2530-minimize-maximum-of-array
2536-determine-if-two-events-have-conflict
2548-destroy-sequential-targets
2551-apply-operations-to-an-array
2600-maximum-tastiness-of-candy-basket
2602-maximum-enemy-forts-that-can-be-captured
2618-maximize-the-minimum-powered-city
2661-smallest-missing-non-negative-integer-after-operations
2689-rearranging-fruits
2720-minimize-the-maximum-difference-of-pairs
2721-sum-of-distances
2753-minimum-number-of-operations-to-make-all-array-elements-equal-to-1
3194-find-words-containing-character
3241-divide-array-into-arrays-with-max-difference
3251-maximum-area-of-longest-diagonal-rectangle
3277-find-the-number-of-ways-to-place-people-ii
3415-check-if-grid-satisfies-conditions
3418-count-pairs-that-form-a-complete-day-ii
3421-count-pairs-that-form-a-complete-day-i
3437-maximum-total-damage-with-spell-casting
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3471-minimum-average-of-smallest-and-largest-elements
3491-find-the-maximum-length-of-valid-subsequence-ii
3501-delete-nodes-from-linked-list-present-in-array
3581-the-two-sneaky-numbers-of-digitville
3592-find-x-sum-of-all-k-long-subarrays-ii
3616-make-array-elements-equal-to-zero
3639-zero-array-transformation-i
3643-zero-array-transformation-ii
3733-length-of-longest-v-shaped-diagonal-segment
3744-minimum-operations-to-make-array-elements-zero
3747-maximum-difference-between-adjacent-elements-in-a-circular-array
3748-sort-matrix-by-diagonals
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3797-design-spreadsheet
3863-power-grid-maintenance

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0240-search-a-2d-matrix-ii
0268-missing-number
0278-first-bad-version
0300-longest-increasing-subsequence
0374-guess-number-higher-or-lower
0436-find-right-interval
0456-132-pattern
0532-k-diff-pairs-in-an-array
0611-valid-triangle-number
0745-find-smallest-letter-greater-than-target
0792-binary-search
0808-number-of-matching-subsequences
0853-most-profit-assigning-work
0912-random-pick-with-weight
1046-max-consecutive-ones-iii
1321-get-equal-substrings-within-budget
1476-count-negative-numbers-in-a-sorted-matrix
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1675-magnetic-force-between-two-balls
1851-maximum-number-of-events-that-can-be-attended-ii
2000-minimum-speed-to-arrive-on-time
2134-maximize-the-confusion-of-an-exam
2150-kth-smallest-product-of-two-sorted-arrays
2165-plates-between-candles
2229-maximum-fruits-harvested-after-at-most-k-steps
2294-minimum-time-to-complete-trips
2392-successful-pairs-of-spells-and-potions
2469-longest-subsequence-with-limited-sum
2498-smallest-subarrays-with-maximum-bitwise-or
2530-minimize-maximum-of-array
2600-maximum-tastiness-of-candy-basket
2618-maximize-the-minimum-powered-city
2720-minimize-the-maximum-difference-of-pairs
3266-find-longest-special-substring-that-occurs-thrice-ii
3267-find-longest-special-substring-that-occurs-thrice-i
3437-maximum-total-damage-with-spell-casting
3643-zero-array-transformation-ii
3790-fruits-into-baskets-ii

Prefix Sum

0912-random-pick-with-weight
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1321-get-equal-substrings-within-budget
1930-unique-length-3-palindromic-subsequences
2134-maximize-the-confusion-of-an-exam
2165-plates-between-candles
2229-maximum-fruits-harvested-after-at-most-k-steps
2240-intervals-between-identical-elements
2469-longest-subsequence-with-limited-sum
2529-range-product-queries-of-powers
2530-minimize-maximum-of-array
2618-maximize-the-minimum-powered-city
2721-sum-of-distances
3616-make-array-elements-equal-to-zero
3618-find-the-original-typed-string-ii
3639-zero-array-transformation-i
3643-zero-array-transformation-ii
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Hash Table

0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0036-valid-sudoku
0139-word-break
0166-fraction-to-recurring-decimal
0169-majority-element
0219-contains-duplicate-ii
0229-majority-element-ii
0268-missing-number
0383-ransom-note
0424-longest-repeating-character-replacement
0442-find-all-duplicates-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0454-4sum-ii
0491-non-decreasing-subsequences
0496-next-greater-element-i
0532-k-diff-pairs-in-an-array
0575-distribute-candies
0594-longest-harmonious-subsequence
0768-partition-labels
0808-number-of-matching-subsequences
0893-all-nodes-distance-k-in-binary-tree
0900-reordered-power-of-2
0966-binary-subarrays-with-sum
1006-vowel-spellchecker
1055-pairs-of-songs-with-total-durations-divisible-by-60
1217-relative-sort-array
1256-rank-transform-of-an-array
1353-find-resultant-array-after-removing-anagrams
1460-number-of-substrings-containing-all-three-characters
1510-find-lucky-integer-in-an-array
1632-number-of-good-ways-to-split-a-string
1813-maximum-erasure-value
1834-minimum-number-of-people-to-teach
1930-unique-length-3-palindromic-subsequences
1995-finding-pairs-with-a-certain-sum
2122-count-special-quadruplets
2169-simple-bank-system
2204-find-subsequence-of-length-k-with-the-largest-sum
2237-longest-palindrome-by-concatenating-two-letter-words
2240-intervals-between-identical-elements
2254-check-if-every-row-and-column-contains-all-numbers
2461-amount-of-time-for-binary-tree-to-be-infected
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2548-destroy-sequential-targets
2661-smallest-missing-non-negative-integer-after-operations
2689-rearranging-fruits
2721-sum-of-distances
3266-find-longest-special-substring-that-occurs-thrice-ii
3267-find-longest-special-substring-that-occurs-thrice-i
3360-minimum-deletions-to-make-string-k-special
3418-count-pairs-that-form-a-complete-day-ii
3421-count-pairs-that-form-a-complete-day-i
3437-maximum-total-damage-with-spell-casting
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
3570-count-of-substrings-containing-every-vowel-and-k-consonants-i
3581-the-two-sneaky-numbers-of-digitville
3592-find-x-sum-of-all-k-long-subarrays-ii
3678-design-task-manager
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3797-design-spreadsheet
3863-power-grid-maintenance
3872-find-most-frequent-vowel-and-consonant

Divide and Conquer

0053-maximum-subarray
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0240-search-a-2d-matrix-ii
0324-wiggle-sort-ii

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0047-permutations-ii
0169-majority-element
0229-majority-element-ii
0268-missing-number
0324-wiggle-sort-ii
0435-non-overlapping-intervals
0436-find-right-interval
0452-minimum-number-of-arrows-to-burst-balloons
0532-k-diff-pairs-in-an-array
0594-longest-harmonious-subsequence
0611-valid-triangle-number
0757-set-intersection-size-at-least-two
0808-number-of-matching-subsequences
0853-most-profit-assigning-work
0900-reordered-power-of-2
1217-relative-sort-array
1256-rank-transform-of-an-array
1306-minimum-absolute-difference
1353-find-resultant-array-after-removing-anagrams
1478-maximum-number-of-events-that-can-be-attended
1519-minimum-subsequence-in-non-increasing-order
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1669-minimum-cost-to-cut-a-stick
1675-magnetic-force-between-two-balls
1851-maximum-number-of-events-that-can-be-attended-ii
2204-find-subsequence-of-length-k-with-the-largest-sum
2248-minimum-cost-of-buying-candies-with-discount
2269-count-elements-with-strictly-smaller-and-greater-elements
2387-partition-array-such-that-maximum-difference-is-k
2392-successful-pairs-of-spells-and-potions
2469-longest-subsequence-with-limited-sum
2497-maximum-matching-of-players-with-trainers
2600-maximum-tastiness-of-candy-basket
2689-rearranging-fruits
2887-sort-vowels-in-a-string
3241-divide-array-into-arrays-with-max-difference
3277-find-the-number-of-ways-to-place-people-ii
3360-minimum-deletions-to-make-string-k-special
3437-maximum-total-damage-with-spell-casting
3471-minimum-average-of-smallest-and-largest-elements
3748-sort-matrix-by-diagonals

Counting

0169-majority-element
0229-majority-element-ii
0383-ransom-note
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1055-pairs-of-songs-with-total-durations-divisible-by-60
1510-find-lucky-integer-in-an-array
2140-longest-subsequence-repeated-k-times
2237-longest-palindrome-by-concatenating-two-letter-words
2269-count-elements-with-strictly-smaller-and-greater-elements
2548-destroy-sequential-targets
3266-find-longest-special-substring-that-occurs-thrice-ii
3267-find-longest-special-substring-that-occurs-thrice-i
3360-minimum-deletions-to-make-string-k-special
3418-count-pairs-that-form-a-complete-day-ii
3421-count-pairs-that-form-a-complete-day-i
3437-maximum-total-damage-with-spell-casting
3753-maximum-difference-between-even-and-odd-frequency-i
3754-maximum-manhattan-distance-after-k-changes
3872-find-most-frequent-vowel-and-consonant

Math

0013-roman-to-integer
0048-rotate-image
0062-unique-paths
0066-plus-one
0150-evaluate-reverse-polish-notation
0166-fraction-to-recurring-decimal
0189-rotate-array
0231-power-of-two
0268-missing-number
0326-power-of-three
0342-power-of-four
0556-next-greater-element-iii
0679-24-game
0826-soup-servings
0867-new-21-game
0900-reordered-power-of-2
0912-random-pick-with-weight
1411-convert-binary-number-in-a-linked-list-to-integer
1426-find-n-unique-integers-sum-up-to-zero
1448-maximum-69-number
1529-max-difference-you-can-get-from-changing-an-integer
1636-number-of-substrings-with-only-1s
1642-water-bottles
1817-calculate-money-in-leetcode-bank
1885-count-number-of-homogenous-substrings
2202-sum-of-k-mirror-numbers
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2432-number-of-zero-filled-subarrays
2661-smallest-missing-non-negative-integer-after-operations
2663-distribute-money-to-maximum-children
2704-maximum-difference-by-remapping-a-digit
2753-minimum-number-of-operations-to-make-all-array-elements-equal-to-1
3172-divisible-and-non-divisible-sums-difference
3199-distribute-candies-among-children-i
3201-distribute-candies-among-children-ii
3277-find-the-number-of-ways-to-place-people-ii
3279-alice-and-bob-playing-flower-game
3336-water-bottles-ii
3462-vowels-game-in-a-string
3581-the-two-sneaky-numbers-of-digitville
3600-find-the-k-th-character-in-string-game-i
3682-count-the-number-of-arrays-with-k-matching-adjacent-elements
3744-minimum-operations-to-make-array-elements-zero
3754-maximum-manhattan-distance-after-k-changes

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0031-next-permutation
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0125-valid-palindrome
0143-reorder-list
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0283-move-zeroes
0392-is-subsequence
0532-k-diff-pairs-in-an-array
0556-next-greater-element-iii
0611-valid-triangle-number
0647-palindromic-substrings
0680-valid-palindrome-ii
0768-partition-labels
0853-most-profit-assigning-work
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2271-rearrange-array-elements-by-sign
2320-find-all-k-distant-indices-in-an-array
2392-successful-pairs-of-spells-and-potions
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array
2602-maximum-enemy-forts-that-can-be-captured
3437-maximum-total-damage-with-spell-casting
3471-minimum-average-of-smallest-and-largest-elements
3683-find-the-lexicographically-largest-string-from-the-box-i

Simulation

0498-diagonal-traverse
1041-available-captures-for-rook
1642-water-bottles
2137-final-value-of-variable-after-performing-operations
2169-simple-bank-system
2260-divide-a-string-into-groups-of-size-k
2271-rearrange-array-elements-by-sign
2324-find-triangular-sum-of-an-array
2343-count-unguarded-cells-in-the-grid
2408-number-of-people-aware-of-a-secret
2551-apply-operations-to-an-array
3336-water-bottles-ii
3600-find-the-k-th-character-in-string-game-i
3616-make-array-elements-equal-to-zero
3790-fruits-into-baskets-ii

Counting Sort

1217-relative-sort-array

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0013-roman-to-integer
0020-valid-parentheses
0022-generate-parentheses
0032-longest-valid-parentheses
0058-length-of-last-word
0071-simplify-path
0072-edit-distance
0079-word-search
0115-distinct-subsequences
0125-valid-palindrome
0131-palindrome-partitioning
0139-word-break
0166-fraction-to-recurring-decimal
0316-remove-duplicate-letters
0383-ransom-note
0392-is-subsequence
0394-decode-string
0424-longest-repeating-character-replacement
0474-ones-and-zeroes
0556-next-greater-element-iii
0583-delete-operation-for-two-strings
0647-palindromic-substrings
0680-valid-palindrome-ii
0768-partition-labels
0808-number-of-matching-subsequences
0916-decoded-string-at-index
1006-vowel-spellchecker
1030-smallest-string-starting-from-leaf
1045-check-if-word-is-valid-after-substitutions
1058-lexicographically-smallest-equivalent-string
1159-smallest-subsequence-of-distinct-characters
1302-delete-characters-to-make-fancy-string
1321-get-equal-substrings-within-budget
1350-remove-sub-folders-from-the-filesystem
1353-find-resultant-array-after-removing-anagrams
1371-minimum-remove-to-make-valid-parentheses
1460-number-of-substrings-containing-all-three-characters
1632-number-of-good-ways-to-split-a-string
1636-number-of-substrings-with-only-1s
1818-maximum-score-from-removing-substrings
1885-count-number-of-homogenous-substrings
1930-unique-length-3-palindromic-subsequences
1967-longest-substring-of-all-vowels-in-order
1999-longer-contiguous-segments-of-ones-than-zeros
2134-maximize-the-confusion-of-an-exam
2137-final-value-of-variable-after-performing-operations
2140-longest-subsequence-repeated-k-times
2165-plates-between-candles
2221-check-if-a-parentheses-string-can-be-valid
2237-longest-palindrome-by-concatenating-two-letter-words
2260-divide-a-string-into-groups-of-size-k
2346-largest-3-same-digit-number-in-string
2395-longest-binary-subsequence-less-than-or-equal-to-k
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2492-length-of-the-longest-alphabetical-continuous-substring
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2536-determine-if-two-events-have-conflict
2887-sort-vowels-in-a-string
3194-find-words-containing-character
3266-find-longest-special-substring-that-occurs-thrice-ii
3267-find-longest-special-substring-that-occurs-thrice-i
3360-minimum-deletions-to-make-string-k-special
3396-valid-word
3445-lexicographically-minimum-string-after-removing-stars
3462-vowels-game-in-a-string
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3570-count-of-substrings-containing-every-vowel-and-k-consonants-i
3617-find-the-original-typed-string-i
3618-find-the-original-typed-string-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
3797-design-spreadsheet
3872-find-most-frequent-vowel-and-consonant

Greedy

0011-container-with-most-water
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0316-remove-duplicate-letters
0324-wiggle-sort-ii
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0605-can-place-flowers
0611-valid-triangle-number
0680-valid-palindrome-ii
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0757-set-intersection-size-at-least-two
0768-partition-labels
0853-most-profit-assigning-work
1159-smallest-subsequence-of-distinct-characters
1448-maximum-69-number
1478-maximum-number-of-events-that-can-be-attended
1519-minimum-subsequence-in-non-increasing-order
1529-max-difference-you-can-get-from-changing-an-integer
1818-maximum-score-from-removing-substrings
1834-minimum-number-of-people-to-teach
1917-maximum-average-pass-ratio
2140-longest-subsequence-repeated-k-times
2221-check-if-a-parentheses-string-can-be-valid
2237-longest-palindrome-by-concatenating-two-letter-words
2248-minimum-cost-of-buying-candies-with-discount
2387-partition-array-such-that-maximum-difference-is-k
2395-longest-binary-subsequence-less-than-or-equal-to-k
2469-longest-subsequence-with-limited-sum
2497-maximum-matching-of-players-with-trainers
2520-using-a-robot-to-print-the-lexicographically-smallest-string
2530-minimize-maximum-of-array
2600-maximum-tastiness-of-candy-basket
2618-maximize-the-minimum-powered-city
2661-smallest-missing-non-negative-integer-after-operations
2663-distribute-money-to-maximum-children
2689-rearranging-fruits
2704-maximum-difference-by-remapping-a-digit
2720-minimize-the-maximum-difference-of-pairs
3241-divide-array-into-arrays-with-max-difference
3360-minimum-deletions-to-make-string-k-special
3445-lexicographically-minimum-string-after-removing-stars

Matrix

0036-valid-sudoku
0048-rotate-image
0063-unique-paths-ii
0074-search-a-2d-matrix
0079-word-search
0200-number-of-islands
0240-search-a-2d-matrix-ii
0417-pacific-atlantic-water-flow
0498-diagonal-traverse
0945-snakes-and-ladders
1022-unique-paths-iii
1041-available-captures-for-rook
1402-count-square-submatrices-with-all-ones
1476-count-negative-numbers-in-a-sorted-matrix
2254-check-if-every-row-and-column-contains-all-numbers
2343-count-unguarded-cells-in-the-grid
3415-check-if-grid-satisfies-conditions
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3733-length-of-longest-v-shaped-diagonal-segment
3748-sort-matrix-by-diagonals
3797-design-spreadsheet

Interactive

0278-first-bad-version
0374-guess-number-higher-or-lower

Database

0175-combine-two-tables
0176-second-highest-salary

Randomized

0912-random-pick-with-weight

Tree

0094-binary-tree-inorder-traversal
0099-recover-binary-search-tree
0101-symmetric-tree
0110-balanced-binary-tree
0112-path-sum
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0437-path-sum-iii
0530-minimum-absolute-difference-in-bst
0572-subtree-of-another-tree
0893-all-nodes-distance-k-in-binary-tree
1030-smallest-string-starting-from-leaf
2400-minimum-score-after-removals-on-a-tree
2461-amount-of-time-for-binary-tree-to-be-infected
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii

Depth-First Search

0079-word-search
0094-binary-tree-inorder-traversal
0099-recover-binary-search-tree
0101-symmetric-tree
0110-balanced-binary-tree
0112-path-sum
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0386-lexicographical-numbers
0417-pacific-atlantic-water-flow
0437-path-sum-iii
0530-minimum-absolute-difference-in-bst
0547-number-of-provinces
0572-subtree-of-another-tree
0801-is-graph-bipartite
0893-all-nodes-distance-k-in-binary-tree
1030-smallest-string-starting-from-leaf
1350-remove-sub-folders-from-the-filesystem
2400-minimum-score-after-removals-on-a-tree
2438-find-closest-node-to-given-two-nodes
2461-amount-of-time-for-binary-tree-to-be-infected
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3863-power-grid-maintenance

Breadth-First Search

0101-symmetric-tree
0112-path-sum
0199-binary-tree-right-side-view
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0417-pacific-atlantic-water-flow
0530-minimum-absolute-difference-in-bst
0547-number-of-provinces
0801-is-graph-bipartite
0893-all-nodes-distance-k-in-binary-tree
0945-snakes-and-ladders
1424-maximum-candies-you-can-get-from-boxes
2461-amount-of-time-for-binary-tree-to-be-infected
3633-maximize-the-number-of-target-nodes-after-connecting-trees-i
3645-maximize-the-number-of-target-nodes-after-connecting-trees-ii
3863-power-grid-maintenance

Union Find

0200-number-of-islands
0547-number-of-provinces
0801-is-graph-bipartite
1058-lexicographically-smallest-equivalent-string
3863-power-grid-maintenance

Graph

0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0801-is-graph-bipartite
1424-maximum-candies-you-can-get-from-boxes
2438-find-closest-node-to-given-two-nodes
3863-power-grid-maintenance

Topological Sort

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

Backtracking

0022-generate-parentheses
0046-permutations
0047-permutations-ii
0077-combinations
0078-subsets
0079-word-search
0113-path-sum-ii
0131-palindrome-partitioning
0491-non-decreasing-subsequences
0679-24-game
1022-unique-paths-iii
1030-smallest-string-starting-from-leaf
1418-fair-distribution-of-cookies
1723-maximum-number-of-achievable-transfer-requests
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets

Bit Manipulation

0078-subsets
0190-reverse-bits
0191-number-of-1-bits
0201-bitwise-and-of-numbers-range
0231-power-of-two
0260-single-number-iii
0268-missing-number
0342-power-of-four
0491-non-decreasing-subsequences
1022-unique-paths-iii
1418-fair-distribution-of-cookies
1632-number-of-good-ways-to-split-a-string
1723-maximum-number-of-achievable-transfer-requests
1930-unique-length-3-palindromic-subsequences
2170-count-number-of-maximum-bitwise-or-subsets
2400-minimum-score-after-removals-on-a-tree
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2529-range-product-queries-of-powers
2837-minimum-operations-to-make-the-integer-zero
3600-find-the-k-th-character-in-string-game-i
3744-minimum-operations-to-make-array-elements-zero

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0032-longest-valid-parentheses
0053-maximum-subarray
0062-unique-paths
0063-unique-paths-ii
0072-edit-distance
0115-distinct-subsequences
0118-pascals-triangle
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
0139-word-break
0152-maximum-product-subarray
0198-house-robber
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0392-is-subsequence
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0474-ones-and-zeroes
0518-coin-change-ii
0583-delete-operation-for-two-strings
0647-palindromic-substrings
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0808-number-of-matching-subsequences
0826-soup-servings
0867-new-21-game
1402-count-square-submatrices-with-all-ones
1418-fair-distribution-of-cookies
1586-longest-subarray-of-1s-after-deleting-one-element
1632-number-of-good-ways-to-split-a-string
1669-minimum-cost-to-cut-a-stick
1851-maximum-number-of-events-that-can-be-attended-ii
2395-longest-binary-subsequence-less-than-or-equal-to-k
2408-number-of-people-aware-of-a-secret
2530-minimize-maximum-of-array
2882-ways-to-express-an-integer-as-sum-of-powers
3437-maximum-total-damage-with-spell-casting
3491-find-the-maximum-length-of-valid-subsequence-ii
3618-find-the-original-typed-string-ii
3733-length-of-longest-v-shaped-diagonal-segment

Combinatorics

0062-unique-paths
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

Enumeration

0900-reordered-power-of-2
1723-maximum-number-of-achievable-transfer-requests
2122-count-special-quadruplets
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets
2202-sum-of-k-mirror-numbers
2837-minimum-operations-to-make-the-integer-zero
3199-distribute-candies-among-children-i
3201-distribute-candies-among-children-ii
3277-find-the-number-of-ways-to-place-people-ii
3459-find-the-minimum-area-to-cover-all-ones-ii
3683-find-the-lexicographically-largest-string-from-the-box-i
3761-maximum-difference-between-even-and-odd-frequency-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Bitmask

1418-fair-distribution-of-cookies

Sliding Window

0003-longest-substring-without-repeating-characters
0219-contains-duplicate-ii
0424-longest-repeating-character-replacement
0594-longest-harmonious-subsequence
0867-new-21-game
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1321-get-equal-substrings-within-budget
1460-number-of-substrings-containing-all-three-characters
1586-longest-subarray-of-1s-after-deleting-one-element
1813-maximum-erasure-value
1967-longest-substring-of-all-vowels-in-order
2134-maximize-the-confusion-of-an-exam
2229-maximum-fruits-harvested-after-at-most-k-steps
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2618-maximize-the-minimum-powered-city
3266-find-longest-special-substring-that-occurs-thrice-ii
3267-find-longest-special-substring-that-occurs-thrice-i
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3570-count-of-substrings-containing-every-vowel-and-k-consonants-i
3592-find-x-sum-of-all-k-long-subarrays-ii
3761-maximum-difference-between-even-and-odd-frequency-ii

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0071-simplify-path
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0150-evaluate-reverse-polish-notation
0316-remove-duplicate-letters
0394-decode-string
0456-132-pattern
0496-next-greater-element-i
0739-daily-temperatures
0916-decoded-string-at-index
1045-check-if-word-is-valid-after-substitutions
1159-smallest-subsequence-of-distinct-characters
1305-number-of-visible-people-in-a-queue
1371-minimum-remove-to-make-valid-parentheses
1818-maximum-score-from-removing-substrings
2221-check-if-a-parentheses-string-can-be-valid
2307-replace-non-coprime-numbers-in-array
2520-using-a-robot-to-print-the-lexicographically-smallest-string
3445-lexicographically-minimum-string-after-removing-stars

Heap (Priority Queue)

1478-maximum-number-of-events-that-can-be-attended
1917-maximum-average-pass-ratio
2204-find-subsequence-of-length-k-with-the-largest-sum
3445-lexicographically-minimum-string-after-removing-stars
3592-find-x-sum-of-all-k-long-subarrays-ii
3678-design-task-manager
3863-power-grid-maintenance

Trie

0139-word-break
0386-lexicographical-numbers
0440-k-th-smallest-in-lexicographical-order
0808-number-of-matching-subsequences
1350-remove-sub-folders-from-the-filesystem

Monotonic Stack

0316-remove-duplicate-letters
0456-132-pattern
0496-next-greater-element-i
0739-daily-temperatures
1159-smallest-subsequence-of-distinct-characters
1305-number-of-visible-people-in-a-queue

Ordered Set

0456-132-pattern
3678-design-task-manager
3790-fruits-into-baskets-ii
3863-power-grid-maintenance

Quickselect

0324-wiggle-sort-ii

Binary Tree

0094-binary-tree-inorder-traversal
0099-recover-binary-search-tree
0101-symmetric-tree
0110-balanced-binary-tree
0112-path-sum
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0199-binary-tree-right-side-view
0437-path-sum-iii
0530-minimum-absolute-difference-in-bst
0572-subtree-of-another-tree
0893-all-nodes-distance-k-in-binary-tree
1030-smallest-string-starting-from-leaf
2461-amount-of-time-for-binary-tree-to-be-infected

Binary Search Tree

0099-recover-binary-search-tree
0530-minimum-absolute-difference-in-bst

Memoization

0139-word-break
2395-longest-binary-subsequence-less-than-or-equal-to-k
3733-length-of-longest-v-shaped-diagonal-segment

Linked List

0024-swap-nodes-in-pairs
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0092-reverse-linked-list-ii
0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0206-reverse-linked-list
0237-delete-node-in-a-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
3501-delete-nodes-from-linked-list-present-in-array

Recursion

0024-swap-nodes-in-pairs
0143-reorder-list
0206-reverse-linked-list
0231-power-of-two
0326-power-of-three
0342-power-of-four
0394-decode-string
3600-find-the-k-th-character-in-string-game-i

String Matching

0572-subtree-of-another-tree

Hash Function

0572-subtree-of-another-tree

Design

1995-finding-pairs-with-a-certain-sum
2169-simple-bank-system
3678-design-task-manager
3797-design-spreadsheet

Segment Tree

3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii

Probability and Statistics

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

Geometry

3277-find-the-number-of-ways-to-place-people-ii

Brainteaser

2837-minimum-operations-to-make-the-integer-zero
3462-vowels-game-in-a-string

Queue

2408-number-of-people-aware-of-a-secret
2618-maximize-the-minimum-powered-city

Game Theory

3462-vowels-game-in-a-string

Number Theory

2307-replace-non-coprime-numbers-in-array
2753-minimum-number-of-operations-to-make-all-array-elements-equal-to-1