Leetcode

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

LeetCode Topics

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0013-roman-to-integer
0029-divide-two-integers
0048-rotate-image
0050-powx-n
0062-unique-paths
0069-sqrtx
0171-excel-sheet-column-number
0189-rotate-array
0202-happy-number
0204-count-primes
0231-power-of-two
0268-missing-number
0326-power-of-three
0342-power-of-four
0509-fibonacci-number
0628-maximum-product-of-three-numbers
0836-rectangle-overlap
0877-stone-game
1006-clumsy-factorial
1248-count-number-of-nice-subarrays
1295-find-numbers-with-even-number-of-digits
1344-angle-between-hands-of-a-clock
1401-circle-and-rectangle-overlapping
1510-stone-game-iv
1523-count-odd-numbers-in-an-interval-range
1563-stone-game-v
1621-number-of-sets-of-k-non-overlapping-line-segments
1812-determine-color-of-a-chessboard-square
1837-sum-of-digits-in-base-k
1872-stone-game-viii
1903-largest-odd-number-in-string
1927-sum-game
1979-find-greatest-common-divisor-of-array
2029-stone-game-ix
2235-add-two-integers
2310-sum-of-numbers-with-units-digit-k
2413-smallest-even-multiple
2582-pass-the-pillow
2769-find-the-maximum-achievable-number
2843-count-symmetric-integers
2965-find-missing-and-repeated-values
3014-minimum-number-of-pushes-to-type-word-i
3116-kth-smallest-amount-with-single-denomination-combination
3227-vowels-game-in-a-string
3300-minimum-element-after-replacement-with-digit-sum
3345-smallest-divisible-digit-product-i
3512-minimum-operations-to-make-array-sum-divisible-by-k
3513-number-of-unique-xor-triplets-i
3514-number-of-unique-xor-triplets-ii
3516-find-closest-person
3524-find-x-value-of-array-i
3536-maximum-product-of-two-digits
3550-smallest-index-with-digit-sum-equal-to-index
3622-check-divisibility-by-digit-sum-and-product
3658-gcd-of-odd-and-even-sums
3723-maximize-sum-of-squares-of-digits
3726-remove-zeros-in-decimal-representation
3736-minimum-moves-to-equal-array-elements-iii
3751-total-waviness-of-numbers-in-range-i
3754-concatenate-non-zero-digits-and-multiply-by-sum-i
3783-mirror-distance-of-an-integer
3867-sum-of-gcd-of-formed-pairs
3870-count-commas-in-range
3871-count-commas-in-range-ii
3875-construct-uniform-parity-array-i
3876-construct-uniform-parity-array-ii

Two Pointers

0005-longest-palindromic-substring
0015-3sum
0018-4sum
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
0042-trapping-rain-water
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0295-find-median-from-data-stream
0344-reverse-string
0392-is-subsequence
0443-string-compression
0455-assign-cookies
0567-permutation-in-string
0832-flipping-an-image
0876-middle-of-the-linked-list
0977-squares-of-a-sorted-array
2095-delete-the-middle-node-of-a-linked-list
2108-find-first-palindromic-string-in-the-array
2130-maximum-twin-sum-of-a-linked-list
2149-rearrange-array-elements-by-sign
2161-partition-array-according-to-given-pivot
2472-maximum-number-of-non-overlapping-palindrome-substrings
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3734-lexicographically-smallest-palindromic-permutation-greater-than-target
3794-reverse-string-prefix
3867-sum-of-gcd-of-formed-pairs

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0008-string-to-integer-atoi
0013-roman-to-integer
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
0032-longest-valid-parentheses
0049-group-anagrams
0076-minimum-window-substring
0079-word-search
0115-distinct-subsequences
0125-valid-palindrome
0131-palindrome-partitioning
0151-reverse-words-in-a-string
0171-excel-sheet-column-number
0179-largest-number
0205-isomorphic-strings
0242-valid-anagram
0301-remove-invalid-parentheses
0344-reverse-string
0387-first-unique-character-in-a-string
0392-is-subsequence
0402-remove-k-digits
0424-longest-repeating-character-replacement
0443-string-compression
0451-sort-characters-by-frequency
0567-permutation-in-string
0657-robot-return-to-origin
0678-valid-parenthesis-string
0709-to-lower-case
0796-rotate-string
0856-score-of-parentheses
0940-distinct-subsequences-ii
1021-remove-outermost-parentheses
1081-smallest-subsequence-of-distinct-characters
1096-brace-expansion-ii
1108-defanging-an-ip-address
1111-maximum-nesting-depth-of-two-valid-parentheses-strings
1189-maximum-number-of-balloons
1358-number-of-substrings-containing-all-three-characters
1487-making-file-names-unique
1520-maximum-number-of-non-overlapping-substrings
1541-minimum-insertions-to-balance-a-parentheses-string
1614-maximum-nesting-depth-of-the-parentheses
1781-sum-of-beauty-of-all-substrings
1784-check-if-binary-string-has-at-most-one-segment-of-ones
1812-determine-color-of-a-chessboard-square
1816-truncate-sentence
1832-check-if-the-sentence-is-pangram
1903-largest-odd-number-in-string
1910-remove-all-occurrences-of-a-substring
1927-sum-game
1967-number-of-strings-that-appear-as-substrings-in-word
1985-find-the-kth-largest-integer-in-the-array
2108-find-first-palindromic-string-in-the-array
2114-maximum-number-of-words-found-in-sentences
2124-check-if-all-as-appears-before-all-bs
2472-maximum-number-of-non-overlapping-palindrome-substrings
2515-shortest-distance-to-target-string-in-a-circular-array
2678-number-of-senior-citizens
2710-remove-trailing-zeros-from-a-string
2716-minimize-string-length
2785-sort-vowels-in-a-string
2833-furthest-point-from-origin
2904-shortest-and-lexicographically-smallest-beautiful-string
2942-find-words-containing-character
3014-minimum-number-of-pushes-to-type-word-i
3016-minimum-number-of-pushes-to-type-word-ii
3043-find-the-length-of-the-longest-common-prefix
3090-maximum-length-substring-with-two-occurrences
3110-score-of-a-string
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3136-valid-word
3174-clear-digits
3227-vowels-game-in-a-string
3498-reverse-degree-of-a-string
3499-maximize-active-section-with-trade-i
3517-smallest-palindromic-rearrangement-i
3541-find-most-frequent-vowel-and-consonant
3612-process-string-with-special-operations-i
3614-process-string-with-special-operations-ii
3720-lexicographically-smallest-permutation-greater-than-target
3734-lexicographically-smallest-palindromic-permutation-greater-than-target
3794-reverse-string-prefix
3813-vowel-consonant-score
3838-weighted-word-mapping
3889-mirror-frequency-distance

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0085-maximal-rectangle
0115-distinct-subsequences
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0131-palindrome-partitioning
0152-maximum-product-subarray
0392-is-subsequence
0509-fibonacci-number
0678-valid-parenthesis-string
0877-stone-game
0907-sum-of-subarray-minimums
0940-distinct-subsequences-ii
1477-find-two-non-overlapping-sub-arrays-each-with-target-sum
1510-stone-game-iv
1563-stone-game-v
1621-number-of-sets-of-k-non-overlapping-line-segments
1872-stone-game-viii
2267-check-if-there-is-a-valid-parentheses-string-path
2310-sum-of-numbers-with-units-digit-k
2472-maximum-number-of-non-overlapping-palindrome-substrings
3524-find-x-value-of-array-i
3751-total-waviness-of-numbers-in-range-i

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0050-powx-n
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four
0509-fibonacci-number
3483-unique-3-digit-even-numbers

Memoization

0509-fibonacci-number

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0014-longest-common-prefix
0015-3sum
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
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0045-jump-game-ii
0048-rotate-image
0049-group-anagrams
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0059-spiral-matrix-ii
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0079-word-search
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0088-merge-sorted-array
0090-subsets-ii
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0134-gas-station
0135-candy
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0169-majority-element
0179-largest-number
0189-rotate-array
0204-count-primes
0215-kth-largest-element-in-an-array
0216-combination-sum-iii
0217-contains-duplicate
0229-majority-element-ii
0238-product-of-array-except-self
0239-sliding-window-maximum
0240-search-a-2d-matrix-ii
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0455-assign-cookies
0485-max-consecutive-ones
0496-next-greater-element-i
0503-next-greater-element-ii
0560-subarray-sum-equals-k
0621-task-scheduler
0628-maximum-product-of-three-numbers
0704-binary-search
0735-asteroid-collision
0744-find-smallest-letter-greater-than-target
0766-toeplitz-matrix
0832-flipping-an-image
0835-image-overlap
0846-hand-of-straights
0852-peak-index-in-a-mountain-array
0860-lemonade-change
0867-transpose-matrix
0875-koko-eating-bananas
0877-stone-game
0904-fruit-into-baskets
0907-sum-of-subarray-minimums
0912-sort-an-array
0930-binary-subarrays-with-sum
0977-squares-of-a-sorted-array
1004-max-consecutive-ones-iii
1011-capacity-to-ship-packages-within-d-days
1248-count-number-of-nice-subarrays
1260-shift-2d-grid
1283-find-the-smallest-divisor-given-a-threshold
1288-remove-covered-intervals
1295-find-numbers-with-even-number-of-digits
1331-rank-transform-of-an-array
1351-count-negative-numbers-in-a-sorted-matrix
1386-cinema-seat-allocation
1423-maximum-points-you-can-obtain-from-cards
1464-maximum-product-of-two-elements-in-an-array
1470-shuffle-the-array
1477-find-two-non-overlapping-sub-arrays-each-with-target-sum
1482-minimum-number-of-days-to-make-m-bouquets
1487-making-file-names-unique
1502-can-make-arithmetic-progression-from-sequence
1539-kth-missing-positive-number
1563-stone-game-v
1572-matrix-diagonal-sum
1658-minimum-operations-to-reduce-x-to-zero
1672-richest-customer-wealth
1732-find-the-highest-altitude
1748-sum-of-unique-elements
1752-check-if-array-is-sorted-and-rotated
1816-truncate-sentence
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1848-minimum-distance-to-the-target-element
1872-stone-game-viii
1901-find-a-peak-element-ii
1920-build-array-from-permutation
1967-number-of-strings-that-appear-as-substrings-in-word
1979-find-greatest-common-divisor-of-array
1985-find-the-kth-largest-integer-in-the-array
1991-find-the-middle-index-in-array
2016-maximum-difference-between-increasing-elements
2022-convert-1d-array-into-2d-array
2029-stone-game-ix
2073-time-needed-to-buy-tickets
2091-removing-minimum-and-maximum-from-array
2104-sum-of-subarray-ranges
2108-find-first-palindromic-string-in-the-array
2114-maximum-number-of-words-found-in-sentences
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2149-rearrange-array-elements-by-sign
2161-partition-array-according-to-given-pivot
2196-create-binary-tree-from-descriptions
2267-check-if-there-is-a-valid-parentheses-string-path
2333-minimum-sum-of-squared-difference
2515-shortest-distance-to-target-string-in-a-circular-array
2553-separate-the-digits-in-an-array
2574-left-and-right-sum-differences
2596-check-knight-tour-configuration
2657-find-the-prefix-common-array-of-two-arrays
2678-number-of-senior-citizens
2778-sum-of-squares-of-special-elements
2784-check-if-array-is-good
2942-find-words-containing-character
2948-make-lexicographically-smallest-array-by-swapping-elements
2958-length-of-longest-subarray-with-at-most-k-frequency
2965-find-missing-and-repeated-values
2974-minimum-number-game
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3020-find-the-maximum-number-of-elements-in-subset
3043-find-the-length-of-the-longest-common-prefix
3069-distribute-elements-into-two-arrays-i
3116-kth-smallest-amount-with-single-denomination-combination
3184-count-pairs-that-form-a-complete-day-i
3300-minimum-element-after-replacement-with-digit-sum
3392-count-subarrays-of-length-three-with-a-condition
3423-maximum-difference-between-adjacent-elements-in-a-circular-array
3471-find-the-largest-almost-missing-integer
3477-fruits-into-baskets-ii
3483-unique-3-digit-even-numbers
3512-minimum-operations-to-make-array-sum-divisible-by-k
3513-number-of-unique-xor-triplets-i
3514-number-of-unique-xor-triplets-ii
3523-make-array-non-decreasing
3524-find-x-value-of-array-i
3550-smallest-index-with-digit-sum-equal-to-index
3568-minimum-moves-to-clean-the-classroom
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3637-trionic-array-i
3689-maximum-total-subarray-value-i
3702-longest-subsequence-with-non-zero-bitwise-xor
3718-smallest-missing-multiple-of-k
3731-find-missing-elements
3736-minimum-moves-to-equal-array-elements-iii
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii
3838-weighted-word-mapping
3867-sum-of-gcd-of-formed-pairs
3875-construct-uniform-parity-array-i
3876-construct-uniform-parity-array-ii
3903-smallest-stable-index-i
3904-smallest-stable-index-ii

Sorting

0015-3sum
0018-4sum
0049-group-anagrams
0056-merge-intervals
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
0242-valid-anagram
0268-missing-number
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0455-assign-cookies
0621-task-scheduler
0628-maximum-product-of-three-numbers
0846-hand-of-straights
0912-sort-an-array
0977-squares-of-a-sorted-array
1096-brace-expansion-ii
1288-remove-covered-intervals
1331-rank-transform-of-an-array
1464-maximum-product-of-two-elements-in-an-array
1502-can-make-arithmetic-progression-from-sequence
1520-maximum-number-of-non-overlapping-substrings
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1985-find-the-kth-largest-integer-in-the-array
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2333-minimum-sum-of-squared-difference
2784-check-if-array-is-good
2785-sort-vowels-in-a-string
2948-make-lexicographically-smallest-array-by-swapping-elements
2974-minimum-number-game
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3016-minimum-number-of-pushes-to-type-word-ii
3517-smallest-palindromic-rearrangement-i
3536-maximum-product-of-two-digits
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3731-find-missing-elements
3867-sum-of-gcd-of-formed-pairs

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0037-sudoku-solver
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0451-sort-characters-by-frequency
0496-next-greater-element-i
0560-subarray-sum-equals-k
0567-permutation-in-string
0621-task-scheduler
0846-hand-of-straights
0904-fruit-into-baskets
0930-binary-subarrays-with-sum
1096-brace-expansion-ii
1189-maximum-number-of-balloons
1248-count-number-of-nice-subarrays
1331-rank-transform-of-an-array
1358-number-of-substrings-containing-all-three-characters
1386-cinema-seat-allocation
1477-find-two-non-overlapping-sub-arrays-each-with-target-sum
1487-making-file-names-unique
1520-maximum-number-of-non-overlapping-substrings
1658-minimum-operations-to-reduce-x-to-zero
1748-sum-of-unique-elements
1781-sum-of-beauty-of-all-substrings
1832-check-if-the-sentence-is-pangram
2196-create-binary-tree-from-descriptions
2657-find-the-prefix-common-array-of-two-arrays
2716-minimize-string-length
2784-check-if-array-is-good
2958-length-of-longest-subarray-with-at-most-k-frequency
2965-find-missing-and-repeated-values
2996-smallest-missing-integer-greater-than-sequential-prefix-sum
3016-minimum-number-of-pushes-to-type-word-ii
3020-find-the-maximum-number-of-elements-in-subset
3043-find-the-length-of-the-longest-common-prefix
3090-maximum-length-substring-with-two-occurrences
3120-count-the-number-of-special-characters-i
3121-count-the-number-of-special-characters-ii
3184-count-pairs-that-form-a-complete-day-i
3471-find-the-largest-almost-missing-integer
3483-unique-3-digit-even-numbers
3541-find-most-frequent-vowel-and-consonant
3568-minimum-moves-to-clean-the-classroom
3718-smallest-missing-multiple-of-k
3720-lexicographically-smallest-permutation-greater-than-target
3731-find-missing-elements
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii
3889-mirror-frequency-distance

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0240-search-a-2d-matrix-ii
0347-top-k-frequent-elements
0912-sort-an-array
1985-find-the-kth-largest-integer-in-the-array
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0451-sort-characters-by-frequency
0621-task-scheduler
1189-maximum-number-of-balloons
1748-sum-of-unique-elements
1781-sum-of-beauty-of-all-substrings
2029-stone-game-ix
2833-furthest-point-from-origin
3016-minimum-number-of-pushes-to-type-word-ii
3184-count-pairs-that-form-a-complete-day-i
3541-find-most-frequent-vowel-and-consonant
3720-lexicographically-smallest-permutation-greater-than-target
3737-count-subarrays-with-majority-element-i
3889-mirror-frequency-distance

Simulation

0054-spiral-matrix
0059-spiral-matrix-ii
0657-robot-return-to-origin
0735-asteroid-collision
0832-flipping-an-image
0867-transpose-matrix
1006-clumsy-factorial
1260-shift-2d-grid
1910-remove-all-occurrences-of-a-substring
1920-build-array-from-permutation
2022-convert-1d-array-into-2d-array
2073-time-needed-to-buy-tickets
2149-rearrange-array-elements-by-sign
2161-partition-array-according-to-given-pivot
2553-separate-the-digits-in-an-array
2582-pass-the-pillow
2596-check-knight-tour-configuration
2974-minimum-number-game
3069-distribute-elements-into-two-arrays-i
3174-clear-digits
3477-fruits-into-baskets-ii
3498-reverse-degree-of-a-string
3612-process-string-with-special-operations-i
3614-process-string-with-special-operations-ii
3726-remove-zeros-in-decimal-representation
3813-vowel-consonant-score
3838-weighted-word-mapping
3867-sum-of-gcd-of-formed-pairs

Matrix

0037-sudoku-solver
0048-rotate-image
0054-spiral-matrix
0059-spiral-matrix-ii
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0085-maximal-rectangle
0240-search-a-2d-matrix-ii
0766-toeplitz-matrix
0832-flipping-an-image
0835-image-overlap
0867-transpose-matrix
1260-shift-2d-grid
1351-count-negative-numbers-in-a-sorted-matrix
1572-matrix-diagonal-sum
1672-richest-customer-wealth
1901-find-a-peak-element-ii
2022-convert-1d-array-into-2d-array
2267-check-if-there-is-a-valid-parentheses-string-path
2596-check-knight-tour-configuration
2965-find-missing-and-repeated-values
3568-minimum-moves-to-clean-the-classroom

Binary Search

0004-median-of-two-sorted-arrays
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0069-sqrtx
0074-search-a-2d-matrix
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0154-find-minimum-in-rotated-sorted-array-ii
0162-find-peak-element
0240-search-a-2d-matrix-ii
0268-missing-number
0287-find-the-duplicate-number
0704-binary-search
0744-find-smallest-letter-greater-than-target
0852-peak-index-in-a-mountain-array
0875-koko-eating-bananas
1004-max-consecutive-ones-iii
1011-capacity-to-ship-packages-within-d-days
1283-find-the-smallest-divisor-given-a-threshold
1351-count-negative-numbers-in-a-sorted-matrix
1477-find-two-non-overlapping-sub-arrays-each-with-target-sum
1482-minimum-number-of-days-to-make-m-bouquets
1539-kth-missing-positive-number
1658-minimum-operations-to-reduce-x-to-zero
1901-find-a-peak-element-ii
2333-minimum-sum-of-squared-difference
3116-kth-smallest-amount-with-single-denomination-combination
3477-fruits-into-baskets-ii
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii

Union-Find

0128-longest-consecutive-sequence
2948-make-lexicographically-smallest-array-by-swapping-elements

Prefix Sum

0238-product-of-array-except-self
0560-subarray-sum-equals-k
0930-binary-subarrays-with-sum
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1423-maximum-points-you-can-obtain-from-cards
1621-number-of-sets-of-k-non-overlapping-line-segments
1658-minimum-operations-to-reduce-x-to-zero
1732-find-the-highest-altitude
1872-stone-game-viii
1991-find-the-middle-index-in-array
2574-left-and-right-sum-differences
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii
3903-smallest-stable-index-i
3904-smallest-stable-index-ii

Bit Manipulation

0029-divide-two-integers
0078-subsets
0090-subsets-ii
0231-power-of-two
0268-missing-number
0287-find-the-duplicate-number
0342-power-of-four
0832-flipping-an-image
1386-cinema-seat-allocation
2220-minimum-bit-flips-to-convert-number
2657-find-the-prefix-common-array-of-two-arrays
3116-kth-smallest-amount-with-single-denomination-combination
3513-number-of-unique-xor-triplets-i
3514-number-of-unique-xor-triplets-ii
3568-minimum-moves-to-clean-the-classroom
3702-longest-subsequence-with-non-zero-bitwise-xor

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0144-binary-tree-preorder-traversal
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0678-valid-parenthesis-string
0735-asteroid-collision
0856-score-of-parentheses
0901-online-stock-span
0907-sum-of-subarray-minimums
1006-clumsy-factorial
1021-remove-outermost-parentheses
1081-smallest-subsequence-of-distinct-characters
1096-brace-expansion-ii
1111-maximum-nesting-depth-of-two-valid-parentheses-strings
1541-minimum-insertions-to-balance-a-parentheses-string
1614-maximum-nesting-depth-of-the-parentheses
1910-remove-all-occurrences-of-a-substring
2104-sum-of-subarray-ranges
2130-maximum-twin-sum-of-a-linked-list
3174-clear-digits
3523-make-array-non-decreasing

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0796-rotate-string

Segment Tree

3477-fruits-into-baskets-ii
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii

Ordered Set

3477-fruits-into-baskets-ii

Brainteaser

3227-vowels-game-in-a-string

Game Theory

0877-stone-game
1510-stone-game-iv
1563-stone-game-v
1872-stone-game-viii
1927-sum-game
2029-stone-game-ix
3227-vowels-game-in-a-string

Greedy

0045-jump-game-ii
0055-jump-game
0134-gas-station
0135-candy
0179-largest-number
0402-remove-k-digits
0455-assign-cookies
0621-task-scheduler
0678-valid-parenthesis-string
0846-hand-of-straights
0860-lemonade-change
1081-smallest-subsequence-of-distinct-characters
1386-cinema-seat-allocation
1520-maximum-number-of-non-overlapping-substrings
1541-minimum-insertions-to-balance-a-parentheses-string
1833-maximum-ice-cream-bars
1846-maximum-element-after-decreasing-and-rearranging
1903-largest-odd-number-in-string
1927-sum-game
2029-stone-game-ix
2091-removing-minimum-and-maximum-from-array
2126-destroying-asteroids
2144-minimum-cost-of-buying-candies-with-discount
2310-sum-of-numbers-with-units-digit-k
2333-minimum-sum-of-squared-difference
2472-maximum-number-of-non-overlapping-palindrome-substrings
3014-minimum-number-of-pushes-to-type-word-i
3016-minimum-number-of-pushes-to-type-word-ii
3523-make-array-non-decreasing
3633-earliest-finish-time-for-land-and-water-rides-i
3635-earliest-finish-time-for-land-and-water-rides-ii
3689-maximum-total-subarray-value-i
3720-lexicographically-smallest-permutation-greater-than-target
3723-maximize-sum-of-squares-of-digits

Enumeration

0204-count-primes
1291-sequential-digits
2310-sum-of-numbers-with-units-digit-k
2778-sum-of-squares-of-special-elements
2843-count-symmetric-integers
3020-find-the-maximum-number-of-elements-in-subset
3345-smallest-divisible-digit-product-i
3483-unique-3-digit-even-numbers
3499-maximize-active-section-with-trade-i
3514-number-of-unique-xor-triplets-ii
3720-lexicographically-smallest-permutation-greater-than-target
3734-lexicographically-smallest-palindromic-permutation-greater-than-target
3751-total-waviness-of-numbers-in-range-i

Number Theory

0204-count-primes
1979-find-greatest-common-divisor-of-array
2413-smallest-even-multiple
3116-kth-smallest-amount-with-single-denomination-combination
3658-gcd-of-odd-and-even-sums
3867-sum-of-gcd-of-formed-pairs

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0025-reverse-nodes-in-k-group
0141-linked-list-cycle
0142-linked-list-cycle-ii
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
0430-flatten-a-multilevel-doubly-linked-list
0876-middle-of-the-linked-list
2058-find-the-minimum-and-maximum-number-of-nodes-between-critical-points
2095-delete-the-middle-node-of-a-linked-list
2130-maximum-twin-sum-of-a-linked-list

Trie

0014-longest-common-prefix
3043-find-the-length-of-the-longest-common-prefix

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0901-online-stock-span
0907-sum-of-subarray-minimums
1081-smallest-subsequence-of-distinct-characters
2104-sum-of-subarray-ranges
3523-make-array-non-decreasing

Combinatorics

0062-unique-paths
1621-number-of-sets-of-k-non-overlapping-line-segments
3116-kth-smallest-amount-with-single-denomination-combination

Merge Sort

0023-merge-k-sorted-lists
0148-sort-list
0912-sort-an-array
3737-count-subarrays-with-majority-element-i
3739-count-subarrays-with-majority-element-ii

Tree

0102-binary-tree-level-order-traversal
0144-binary-tree-preorder-traversal
0703-kth-largest-element-in-a-stream
2196-create-binary-tree-from-descriptions
2265-count-nodes-equal-to-average-of-subtree

Binary Tree

0102-binary-tree-level-order-traversal
0144-binary-tree-preorder-traversal
0703-kth-largest-element-in-a-stream
2196-create-binary-tree-from-descriptions
2265-count-nodes-equal-to-average-of-subtree

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0567-permutation-in-string
0904-fruit-into-baskets
0930-binary-subarrays-with-sum
1004-max-consecutive-ones-iii
1248-count-number-of-nice-subarrays
1358-number-of-substrings-containing-all-three-characters
1423-maximum-points-you-can-obtain-from-cards
1477-find-two-non-overlapping-sub-arrays-each-with-target-sum
1658-minimum-operations-to-reduce-x-to-zero
2904-shortest-and-lexicographically-smallest-beautiful-string
2958-length-of-longest-subarray-with-at-most-k-frequency
3090-maximum-length-substring-with-two-occurrences

Depth-First Search

0079-word-search
0144-binary-tree-preorder-traversal
0430-flatten-a-multilevel-doubly-linked-list
2265-count-nodes-equal-to-average-of-subtree
2596-check-knight-tour-configuration

Doubly-Linked List

0146-lru-cache
0430-flatten-a-multilevel-doubly-linked-list

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0051-n-queens
0078-subsets
0079-word-search
0090-subsets-ii
0131-palindrome-partitioning
0216-combination-sum-iii
0301-remove-invalid-parentheses
1096-brace-expansion-ii

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0621-task-scheduler
0703-kth-largest-element-in-a-stream
0912-sort-an-array
1464-maximum-product-of-two-elements-in-an-array
1985-find-the-kth-largest-integer-in-the-array
2333-minimum-sum-of-squared-difference
2974-minimum-number-game

Bucket Sort

0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0912-sort-an-array

Counting Sort

0912-sort-an-array
1833-maximum-ice-cream-bars
3517-smallest-palindromic-rearrangement-i

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1985-find-the-kth-largest-integer-in-the-array

Breadth-First Search

0102-binary-tree-level-order-traversal
0301-remove-invalid-parentheses
1096-brace-expansion-ii
2596-check-knight-tour-configuration
3568-minimum-moves-to-clean-the-classroom

Radix Sort

0912-sort-an-array

Design

0146-lru-cache
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0703-kth-largest-element-in-a-stream
0901-online-stock-span

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
0387-first-unique-character-in-a-string
2073-time-needed-to-buy-tickets

Range Minimum/Maximum Query

0084-largest-rectangle-in-histogram
0239-sliding-window-maximum

Monotonic Queue

0239-sliding-window-maximum

Data Stream

0295-find-median-from-data-stream
0703-kth-largest-element-in-a-stream
0901-online-stock-span

Minimax

1510-stone-game-iv
1872-stone-game-viii
2029-stone-game-ix

Nim Game

1510-stone-game-iv
2029-stone-game-ix

Sprague–Grundy Theorem

1510-stone-game-iv

Zero-Sum Game

1510-stone-game-iv
1872-stone-game-viii
2029-stone-game-ix

Tournament Sort

0023-merge-k-sorted-lists

Binary Search Tree

0703-kth-largest-element-in-a-stream

Quicksort

0455-assign-cookies

Bracket Sequences

0020-valid-parentheses
0022-generate-parentheses
0032-longest-valid-parentheses
0678-valid-parenthesis-string
0856-score-of-parentheses
1021-remove-outermost-parentheses
1111-maximum-nesting-depth-of-two-valid-parentheses-strings
1541-minimum-insertions-to-balance-a-parentheses-string
1614-maximum-nesting-depth-of-the-parentheses
2267-check-if-there-is-a-valid-parentheses-string-path

Geometry

0836-rectangle-overlap
1401-circle-and-rectangle-overlapping

Database

0175-combine-two-tables
0176-second-highest-salary
0183-customers-who-never-order
0595-big-countries
1148-article-views-i
1667-fix-names-in-a-table
1683-invalid-tweets
1757-recyclable-and-low-fat-products

Boyer–Moore Majority Vote Algorithm

0169-majority-element