LeetCode Topics

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0036-valid-sudoku
0037-sudoku-solver
0042-trapping-rain-water
0053-maximum-subarray
0066-plus-one
0074-search-a-2d-matrix
0075-sort-colors
0081-search-in-rotated-sorted-array-ii
0085-maximal-rectangle
0088-merge-sorted-array
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0136-single-number
0137-single-number-ii
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
0204-count-primes
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0240-search-a-2d-matrix-ii
0260-single-number-iii
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0368-largest-divisible-subset
0407-trapping-rain-water-ii
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0442-find-all-duplicates-in-an-array
0485-max-consecutive-ones
0498-diagonal-traverse
0540-single-element-in-a-sorted-array
0594-longest-harmonious-subsequence
0611-valid-triangle-number
0628-maximum-product-of-three-numbers
0679-24-game
0717-1-bit-and-2-bit-characters
0724-find-pivot-index
0759-set-intersection-size-at-least-two
0792-binary-search
0794-swim-in-rising-water
0830-largest-triangle-area
0879-maximize-distance-to-closest-person
0882-peak-index-in-a-mountain-array
0905-length-of-longest-fibonacci-subsequence
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
0961-n-repeated-element-in-size-2n-array
0977-squares-of-a-sorted-array
1018-largest-perimeter-triangle
1019-squares-of-a-sorted-array
1111-minimum-score-triangulation-of-polygon
1185-find-in-mountain-array
1200-minimum-absolute-difference
1221-element-appearing-more-than-25-in-sorted-array
1266-minimum-time-visiting-all-points
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1293-three-consecutive-odds
1319-unique-number-of-occurrences
1335-maximum-candies-allocated-to-k-children
1350-remove-sub-folders-from-the-filesystem
1351-count-negative-numbers-in-a-sorted-matrix
1390-four-divisors
1402-count-square-submatrices-with-all-ones
1426-find-n-unique-integers-sum-up-to-zero
1458-max-dot-product-of-two-subsequences
1470-shuffle-the-array
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1524-string-matching-in-an-array
1548-check-if-all-1s-are-at-least-length-k-places-away
1574-maximum-product-of-two-elements-in-an-array
1580-shuffle-the-array
1586-longest-subarray-of-1s-after-deleting-one-element
1603-running-sum-of-1d-array
1612-avoid-flood-in-the-city
1628-count-submatrices-with-all-ones
1635-number-of-good-pairs
1813-maximum-erasure-value
1834-minimum-number-of-people-to-teach
1848-sum-of-unique-elements
1849-maximum-absolute-sum-of-any-subarray
1851-maximum-number-of-events-that-can-be-attended-ii
1877-minimize-maximum-pair-sum-in-array
1886-minimum-limit-of-balls-in-a-bag
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1895-largest-magic-square
1917-maximum-average-pass-ratio
1929-concatenation-of-array
1950-sign-of-the-product-of-an-array
1975-maximum-matrix-sum
1984-minimum-difference-between-highest-and-lowest-of-k-scores
1993-sum-of-all-subset-xor-totals
1995-finding-pairs-with-a-certain-sum
2023-design-movie-rental-system
2058-concatenation-of-array
2079-delete-duplicate-folders-in-system
2102-find-the-middle-index-in-array
2106-find-greatest-common-divisor-of-array
2145-grid-game
2160-minimum-operations-to-make-a-uni-value-grid
2170-count-number-of-maximum-bitwise-or-subsets
2181-smallest-index-with-equal-value
2220-find-all-possible-recipes-from-given-supplies
2229-maximum-fruits-harvested-after-at-most-k-steps
2262-solving-questions-with-brainpower
2265-partition-array-according-to-given-pivot
2267-minimum-difference-in-sums-after-removal-of-elements
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2292-counting-words-with-a-given-prefix
2307-replace-non-coprime-numbers-in-array
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2324-find-triangular-sum-of-an-array
2358-number-of-ways-to-split-array
2400-minimum-score-after-removals-on-a-tree
2429-design-a-food-rating-system
2432-number-of-zero-filled-subarrays
2465-shifting-letters-ii
2478-longest-nice-subarray
2479-meeting-rooms-iii
2486-most-frequent-even-element
2497-maximum-matching-of-players-with-trainers
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2529-range-product-queries-of-powers
2551-apply-operations-to-an-array
2588-maximum-number-of-points-from-grid-queries
2614-maximum-count-of-positive-integer-and-negative-integer
2643-row-with-maximum-ones
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2689-rearranging-fruits
2690-house-robber-iv
2707-merge-two-2d-arrays-by-summing-values
2714-left-and-right-sum-differences
2836-neither-minimum-nor-maximum
2888-minimum-index-of-a-valid-split
2943-maximize-area-of-square-hole-in-grid
2975-maximum-square-area-by-removing-fences-from-a-field
3001-apply-operations-to-maximize-score
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3047-find-the-largest-area-of-square-inside-two-rectangles
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3227-find-missing-and-repeated-values
3242-count-elements-with-maximum-frequency
3251-maximum-area-of-longest-diagonal-rectangle
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3309-count-prefix-and-suffix-pairs-i
3314-construct-the-minimum-bitwise-array-i
3315-construct-the-minimum-bitwise-array-ii
3332-minimum-operations-to-exceed-threshold-value-ii
3348-minimum-cost-walk-in-weighted-graph
3379-transformed-array
3428-find-the-xor-of-numbers-which-appear-twice
3430-count-days-without-meetings
3437-maximum-total-damage-with-spell-casting
3453-separate-squares-i
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3621-minimum-operations-to-make-array-values-equal-to-k
3634-minimum-removals-to-balance-array
3637-trionic-array-i
3640-trionic-array-ii
3643-zero-array-transformation-ii
3648-find-the-maximum-number-of-fruits-collected
3656-minimum-number-of-operations-to-make-elements-in-array-distinct
3657-check-if-grid-can-be-cut-into-sections
3733-length-of-longest-v-shaped-diagonal-segment
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3744-minimum-operations-to-make-array-elements-zero
3748-sort-matrix-by-diagonals
3778-transform-array-by-parity
3788-maximum-unique-subarray-sum-after-deletion
3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3794-find-the-minimum-amount-of-time-to-brew-potions
3797-design-spreadsheet
3827-implement-router
3851-find-sum-of-array-product-of-magical-sequences

Hash Table

0001-two-sum
0036-valid-sudoku
0037-sudoku-solver
0166-fraction-to-recurring-decimal
0169-majority-element
0205-isomorphic-strings
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0442-find-all-duplicates-in-an-array
0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
0768-partition-labels
0865-smallest-subtree-with-all-the-deepest-nodes
0900-reordered-power-of-2
0905-length-of-longest-fibonacci-subsequence
0940-fruit-into-baskets
0961-n-repeated-element-in-size-2n-array
1218-lowest-common-ancestor-of-deepest-leaves
1264-maximum-number-of-words-you-can-type
1319-unique-number-of-occurrences
1460-number-of-substrings-containing-all-three-characters
1502-construct-k-palindrome-strings
1510-find-lucky-integer-in-an-array
1612-avoid-flood-in-the-city
1635-number-of-good-pairs
1813-maximum-erasure-value
1834-minimum-number-of-people-to-teach
1848-sum-of-unique-elements
1930-unique-length-3-palindromic-subsequences
1995-finding-pairs-with-a-certain-sum
2023-design-movie-rental-system
2079-delete-duplicate-folders-in-system
2220-find-all-possible-recipes-from-given-supplies
2274-keep-multiplying-found-values-by-two
2308-divide-array-into-equal-pairs
2429-design-a-food-rating-system
2479-meeting-rooms-iii
2486-most-frequent-even-element
2689-rearranging-fruits
2707-merge-two-2d-arrays-by-summing-values
2888-minimum-index-of-a-valid-split
2975-maximum-square-area-by-removing-fences-from-a-field
3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3227-find-missing-and-repeated-values
3242-count-elements-with-maximum-frequency
3428-find-the-xor-of-numbers-which-appear-twice
3437-maximum-total-damage-with-spell-casting
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
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
3678-design-task-manager
3788-maximum-unique-subarray-sum-after-deletion
3797-design-spreadsheet
3827-implement-router
3872-find-most-frequent-vowel-and-consonant

Two Pointers

0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0151-reverse-words-in-a-string
0165-compare-version-numbers
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0611-valid-triangle-number
0680-valid-palindrome-ii
0768-partition-labels
0977-squares-of-a-sorted-array
1019-squares-of-a-sorted-array
1877-minimize-maximum-pair-sum-in-array
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2481-strictly-palindromic-number
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array
2588-maximum-number-of-points-from-grid-queries
2707-merge-two-2d-arrays-by-summing-values
3437-maximum-total-damage-with-spell-casting

Sorting

0015-3sum
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0368-largest-divisible-subset
0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
0611-valid-triangle-number
0628-maximum-product-of-three-numbers
0759-set-intersection-size-at-least-two
0900-reordered-power-of-2
0977-squares-of-a-sorted-array
1018-largest-perimeter-triangle
1019-squares-of-a-sorted-array
1200-minimum-absolute-difference
1478-maximum-number-of-events-that-can-be-attended
1574-maximum-product-of-two-elements-in-an-array
1851-maximum-number-of-events-that-can-be-attended-ii
1877-minimize-maximum-pair-sum-in-array
1984-minimum-difference-between-highest-and-lowest-of-k-scores
2160-minimum-operations-to-make-a-uni-value-grid
2274-keep-multiplying-found-values-by-two
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
2689-rearranging-fruits
2836-neither-minimum-nor-maximum
2887-sort-vowels-in-a-string
2888-minimum-index-of-a-valid-split
2943-maximize-area-of-square-hole-in-grid
3001-apply-operations-to-maximize-score
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3430-count-days-without-meetings
3437-maximum-total-damage-with-spell-casting
3634-minimum-removals-to-balance-array
3657-check-if-grid-can-be-cut-into-sections
3748-sort-matrix-by-diagonals
3778-transform-array-by-parity

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0029-divide-two-integers
0050-powx-n
0066-plus-one
0069-sqrtx
0166-fraction-to-recurring-decimal
0189-rotate-array
0204-count-primes
0231-power-of-two
0268-missing-number
0326-power-of-three
0342-power-of-four
0367-valid-perfect-square
0368-largest-divisible-subset
0412-fizz-buzz
0628-maximum-product-of-three-numbers
0679-24-game
0826-soup-servings
0830-largest-triangle-area
0867-new-21-game
0900-reordered-power-of-2
1013-fibonacci-number
1018-largest-perimeter-triangle
1236-n-th-tribonacci-number
1266-minimum-time-visiting-all-points
1390-four-divisors
1411-convert-binary-number-in-a-linked-list-to-integer
1426-find-n-unique-integers-sum-up-to-zero
1440-convert-integer-to-the-sum-of-two-no-zero-integers
1448-maximum-69-number
1635-number-of-good-pairs
1889-check-if-number-is-a-sum-of-powers-of-three
1950-sign-of-the-product-of-an-array
1993-sum-of-all-subset-xor-totals
2032-largest-odd-number-in-string
2050-count-good-numbers
2083-three-divisors
2106-find-greatest-common-divisor-of-array
2160-minimum-operations-to-make-a-uni-value-grid
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2432-number-of-zero-filled-subarrays
2481-strictly-palindromic-number
2491-smallest-even-multiple
2575-minimum-cuts-to-divide-a-circle
2610-closest-prime-numbers-in-range
2649-count-total-number-of-colored-cells
2998-count-symmetric-integers
3001-apply-operations-to-maximize-score
3047-find-the-largest-area-of-square-inside-two-rectangles
3227-find-missing-and-repeated-values
3243-count-the-number-of-powerful-integers
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3279-alice-and-bob-playing-flower-game
3336-water-bottles-ii
3462-vowels-game-in-a-string
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3744-minimum-operations-to-make-array-elements-zero
3830-find-closest-person
3851-find-sum-of-array-product-of-magical-sequences

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
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
0167-two-sum-ii-input-array-is-sorted
0240-search-a-2d-matrix-ii
0268-missing-number
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0350-intersection-of-two-arrays-ii
0367-valid-perfect-square
0540-single-element-in-a-sorted-array
0611-valid-triangle-number
0792-binary-search
0794-swim-in-rising-water
0882-peak-index-in-a-mountain-array
1185-find-in-mountain-array
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1335-maximum-candies-allocated-to-k-children
1351-count-negative-numbers-in-a-sorted-matrix
1612-avoid-flood-in-the-city
1851-maximum-number-of-events-that-can-be-attended-ii
1886-minimum-limit-of-balls-in-a-bag
2229-maximum-fruits-harvested-after-at-most-k-steps
2498-smallest-subarrays-with-maximum-bitwise-or
2614-maximum-count-of-positive-integer-and-negative-integer
2665-minimum-time-to-repair-cars
2690-house-robber-iv
3437-maximum-total-damage-with-spell-casting
3453-separate-squares-i
3643-zero-array-transformation-ii
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3827-implement-router

Bit Manipulation

0029-divide-two-integers
0136-single-number
0137-single-number-ii
0231-power-of-two
0260-single-number-iii
0268-missing-number
0287-find-the-duplicate-number
0342-power-of-four
0934-bitwise-ors-of-subarrays
1930-unique-length-3-palindromic-subsequences
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets
2308-divide-array-into-equal-pairs
2400-minimum-score-after-removals-on-a-tree
2478-longest-nice-subarray
2498-smallest-subarrays-with-maximum-bitwise-or
2503-longest-subarray-with-maximum-bitwise-and
2529-range-product-queries-of-powers
2837-minimum-operations-to-make-the-integer-zero
3314-construct-the-minimum-bitwise-array-i
3315-construct-the-minimum-bitwise-array-ii
3348-minimum-cost-walk-in-weighted-graph
3428-find-the-xor-of-numbers-which-appear-twice
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii
3744-minimum-operations-to-make-array-elements-zero
3851-find-sum-of-array-product-of-magical-sequences
3930-longest-palindromic-path-in-graph

Matrix

0036-valid-sudoku
0037-sudoku-solver
0074-search-a-2d-matrix
0085-maximal-rectangle
0240-search-a-2d-matrix-ii
0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0498-diagonal-traverse
0794-swim-in-rising-water
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1351-count-negative-numbers-in-a-sorted-matrix
1402-count-square-submatrices-with-all-ones
1628-count-submatrices-with-all-ones
1895-largest-magic-square
1975-maximum-matrix-sum
2145-grid-game
2160-minimum-operations-to-make-a-uni-value-grid
2588-maximum-number-of-points-from-grid-queries
2643-row-with-maximum-ones
3227-find-missing-and-repeated-values
3459-find-the-minimum-area-to-cover-all-ones-ii
3461-find-the-minimum-area-to-cover-all-ones-i
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment
3748-sort-matrix-by-diagonals
3797-design-spreadsheet

Divide and Conquer

0053-maximum-subarray
0169-majority-element
0215-kth-largest-element-in-an-array
0240-search-a-2d-matrix-ii

String

0014-longest-common-prefix
0020-valid-parentheses
0125-valid-palindrome
0151-reverse-words-in-a-string
0165-compare-version-numbers
0166-fraction-to-recurring-decimal
0205-isomorphic-strings
0242-valid-anagram
0344-reverse-string
0412-fizz-buzz
0451-sort-characters-by-frequency
0680-valid-palindrome-ii
0712-minimum-ascii-delete-sum-for-two-strings
0742-to-lower-case
0768-partition-labels
1128-remove-all-adjacent-duplicates-in-string
1170-shortest-common-supersequence
1264-maximum-number-of-words-you-can-type
1302-delete-characters-to-make-fancy-string
1350-remove-sub-folders-from-the-filesystem
1460-number-of-substrings-containing-all-three-characters
1502-construct-k-palindrome-strings
1524-string-matching-in-an-array
1653-minimum-deletions-to-make-string-balanced
1818-maximum-score-from-removing-substrings
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1930-unique-length-3-palindromic-subsequences
2021-remove-all-occurrences-of-a-substring
2032-largest-odd-number-in-string
2079-delete-duplicate-folders-in-system
2220-find-all-possible-recipes-from-given-supplies
2292-counting-words-with-a-given-prefix
2429-design-a-food-rating-system
2463-minimum-recolors-to-get-k-consecutive-black-blocks
2465-shifting-letters-ii
2887-sort-vowels-in-a-string
3110-score-of-a-string
3243-count-the-number-of-powerful-integers
3309-count-prefix-and-suffix-pairs-i
3396-valid-word
3462-vowels-game-in-a-string
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3617-find-the-original-typed-string-i
3618-find-the-original-typed-string-ii
3797-design-spreadsheet
3872-find-most-frequent-vowel-and-consonant
3930-longest-palindromic-path-in-graph

Stack

0020-valid-parentheses
0042-trapping-rain-water
0085-maximal-rectangle
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
1128-remove-all-adjacent-duplicates-in-string
1628-count-submatrices-with-all-ones
1653-minimum-deletions-to-make-string-balanced
1818-maximum-score-from-removing-substrings
2021-remove-all-occurrences-of-a-substring
2307-replace-non-coprime-numbers-in-array
3001-apply-operations-to-maximize-score

Simulation

0412-fizz-buzz
0498-diagonal-traverse
1929-concatenation-of-array
2021-remove-all-occurrences-of-a-substring
2058-concatenation-of-array
2265-partition-array-according-to-given-pivot
2271-rearrange-array-elements-by-sign
2274-keep-multiplying-found-values-by-two
2324-find-triangular-sum-of-an-array
2408-number-of-people-aware-of-a-secret
2479-meeting-rooms-iii
2551-apply-operations-to-an-array
3332-minimum-operations-to-exceed-threshold-value-ii
3336-water-bottles-ii
3379-transformed-array
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3600-find-the-k-th-character-in-string-game-i
3790-fruits-into-baskets-ii
3794-find-the-minimum-amount-of-time-to-brew-potions

Prefix Sum

0724-find-pivot-index
1292-maximum-side-length-of-a-square-with-sum-less-than-or-equal-to-threshold
1603-running-sum-of-1d-array
1895-minimum-number-of-operations-to-move-all-balls-to-each-box
1895-largest-magic-square
1930-unique-length-3-palindromic-subsequences
2102-find-the-middle-index-in-array
2145-grid-game
2229-maximum-fruits-harvested-after-at-most-k-steps
2358-number-of-ways-to-split-array
2465-shifting-letters-ii
2529-range-product-queries-of-powers
2714-left-and-right-sum-differences
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3618-find-the-original-typed-string-ii
3643-zero-array-transformation-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair
3794-find-the-minimum-amount-of-time-to-brew-potions

Linked List

0002-add-two-numbers
0024-swap-nodes-in-pairs
0061-rotate-list
0328-odd-even-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii

Recursion

0002-add-two-numbers
0024-swap-nodes-in-pairs
0050-powx-n
0231-power-of-two
0326-power-of-three
0342-power-of-four
1013-fibonacci-number
2050-count-good-numbers
3600-find-the-k-th-character-in-string-game-i
3601-find-the-k-th-character-in-string-game-ii

String Matching

1524-string-matching-in-an-array
2292-counting-words-with-a-given-prefix
3309-count-prefix-and-suffix-pairs-i

Trie

0014-longest-common-prefix
1350-remove-sub-folders-from-the-filesystem
2079-delete-duplicate-folders-in-system
3309-count-prefix-and-suffix-pairs-i

Rolling Hash

3309-count-prefix-and-suffix-pairs-i

Hash Function

2079-delete-duplicate-folders-in-system
3309-count-prefix-and-suffix-pairs-i

Greedy

0011-container-with-most-water
0611-valid-triangle-number
0680-valid-palindrome-ii
0759-set-intersection-size-at-least-two
0768-partition-labels
1018-largest-perimeter-triangle
1448-maximum-69-number
1478-maximum-number-of-events-that-can-be-attended
1502-construct-k-palindrome-strings
1612-avoid-flood-in-the-city
1818-maximum-score-from-removing-substrings
1834-minimum-number-of-people-to-teach
1877-minimize-maximum-pair-sum-in-array
1917-maximum-average-pass-ratio
1975-maximum-matrix-sum
2032-largest-odd-number-in-string
2497-maximum-matching-of-players-with-trainers
2681-put-marbles-in-bags
2689-rearranging-fruits
3001-apply-operations-to-maximize-score
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3788-maximum-unique-subarray-sum-after-deletion

Counting

0169-majority-element
0229-majority-element-ii
0451-sort-characters-by-frequency
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1502-construct-k-palindrome-strings
1510-find-lucky-integer-in-an-array
1635-number-of-good-pairs
1848-sum-of-unique-elements
2308-divide-array-into-equal-pairs
2486-most-frequent-even-element
2614-maximum-count-of-positive-integer-and-negative-integer
3242-count-elements-with-maximum-frequency
3437-maximum-total-damage-with-spell-casting
3778-transform-array-by-parity
3872-find-most-frequent-vowel-and-consonant

Interactive

1185-find-in-mountain-array

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0407-trapping-rain-water-ii
0451-sort-characters-by-frequency
0794-swim-in-rising-water
1478-maximum-number-of-events-that-can-be-attended
1574-maximum-product-of-two-elements-in-an-array
1612-avoid-flood-in-the-city
1917-maximum-average-pass-ratio
2023-design-movie-rental-system
2267-minimum-difference-in-sums-after-removal-of-elements
2429-design-a-food-rating-system
2479-meeting-rooms-iii
2588-maximum-number-of-points-from-grid-queries
2681-put-marbles-in-bags
3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3332-minimum-operations-to-exceed-threshold-value-ii
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3678-design-task-manager

Enumeration

0204-count-primes
0900-reordered-power-of-2
1993-sum-of-all-subset-xor-totals
2083-three-divisors
2170-count-number-of-maximum-bitwise-or-subsets
2837-minimum-operations-to-make-the-integer-zero
2975-maximum-square-area-by-removing-fences-from-a-field
2998-count-symmetric-integers
3010-divide-an-array-into-subarrays-with-minimum-cost-i
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3459-find-the-minimum-area-to-cover-all-ones-ii
3741-reschedule-meetings-for-maximum-free-time-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair

Number Theory

0204-count-primes
2083-three-divisors
2106-find-greatest-common-divisor-of-array
2307-replace-non-coprime-numbers-in-array
2491-smallest-even-multiple
2610-closest-prime-numbers-in-range
3001-apply-operations-to-maximize-score

Dynamic Programming

0042-trapping-rain-water
0053-maximum-subarray
0085-maximal-rectangle
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0152-maximum-product-subarray
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0712-minimum-ascii-delete-sum-for-two-strings
0826-soup-servings
0867-new-21-game
0905-length-of-longest-fibonacci-subsequence
0934-bitwise-ors-of-subarrays
1013-fibonacci-number
1111-minimum-score-triangulation-of-polygon
1170-shortest-common-supersequence
1236-n-th-tribonacci-number
1402-count-square-submatrices-with-all-ones
1411-number-of-ways-to-paint-n-3-grid
1458-max-dot-product-of-two-subsequences
1586-longest-subarray-of-1s-after-deleting-one-element
1628-count-submatrices-with-all-ones
1653-minimum-deletions-to-make-string-balanced
1849-maximum-absolute-sum-of-any-subarray
1851-maximum-number-of-events-that-can-be-attended-ii
2028-the-earliest-and-latest-rounds-where-players-compete
2090-number-of-ways-to-arrive-at-destination
2262-solving-questions-with-brainpower
2267-minimum-difference-in-sums-after-removal-of-elements
2408-number-of-people-aware-of-a-secret
2882-ways-to-express-an-integer-as-sum-of-powers
3243-count-the-number-of-powerful-integers
3437-maximum-total-damage-with-spell-casting
3490-find-the-maximum-length-of-valid-subsequence-i
3491-find-the-maximum-length-of-valid-subsequence-ii
3618-find-the-original-typed-string-ii
3640-trionic-array-ii
3648-find-the-maximum-number-of-fruits-collected
3733-length-of-longest-v-shaped-diagonal-segment
3851-find-sum-of-array-product-of-magical-sequences
3930-longest-palindromic-path-in-graph

Sliding Window

0594-longest-harmonious-subsequence
0867-new-21-game
0940-fruit-into-baskets
1460-number-of-substrings-containing-all-three-characters
1586-longest-subarray-of-1s-after-deleting-one-element
1813-maximum-erasure-value
1984-minimum-difference-between-highest-and-lowest-of-k-scores
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
3013-divide-an-array-into-subarrays-with-minimum-cost-ii
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3634-minimum-removals-to-balance-array
3743-reschedule-meetings-for-maximum-free-time-i

Queue

2408-number-of-people-aware-of-a-secret
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3827-implement-router

Union Find

0794-swim-in-rising-water
2588-maximum-number-of-points-from-grid-queries
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph

Graph

2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph
3930-longest-palindromic-path-in-graph

Topological Sort

2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies

Depth-First Search

0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0417-pacific-atlantic-water-flow
0794-swim-in-rising-water
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1339-maximum-product-of-splitted-binary-tree
1350-remove-sub-folders-from-the-filesystem
2400-minimum-score-after-removals-on-a-tree
2793-count-the-number-of-complete-components

Breadth-First Search

0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0794-swim-in-rising-water
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
2588-maximum-number-of-points-from-grid-queries
2793-count-the-number-of-complete-components

Shortest Path

2090-number-of-ways-to-arrive-at-destination

Monotonic Stack

0042-trapping-rain-water
0085-maximal-rectangle
1628-count-submatrices-with-all-ones
3001-apply-operations-to-maximize-score

Tree

0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1339-maximum-product-of-splitted-binary-tree
2400-minimum-score-after-removals-on-a-tree

Binary Tree

0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0865-smallest-subtree-with-all-the-deepest-nodes
1161-maximum-level-sum-of-a-binary-tree
1218-lowest-common-ancestor-of-deepest-leaves
1339-maximum-product-of-splitted-binary-tree

Backtracking

0037-sudoku-solver
0679-24-game
1993-sum-of-all-subset-xor-totals
2170-count-number-of-maximum-bitwise-or-subsets

Combinatorics

1993-sum-of-all-subset-xor-totals
2324-find-triangular-sum-of-an-array
3851-find-sum-of-array-product-of-magical-sequences

Memoization

1013-fibonacci-number
1236-n-th-tribonacci-number
2028-the-earliest-and-latest-rounds-where-players-compete
3733-length-of-longest-v-shaped-diagonal-segment

Quickselect

0215-kth-largest-element-in-an-array

Geometry

0830-largest-triangle-area
1266-minimum-time-visiting-all-points
2575-minimum-cuts-to-divide-a-circle
3047-find-the-largest-area-of-square-inside-two-rectangles
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i

Design

1995-finding-pairs-with-a-certain-sum
2023-design-movie-rental-system
2429-design-a-food-rating-system
3678-design-task-manager
3797-design-spreadsheet
3827-implement-router

Segment Tree

3789-maximize-subarrays-after-removing-one-conflicting-pair
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Database

0176-second-highest-salary
0584-find-customer-referee
0595-big-countries
1258-article-views-i
1827-invalid-tweets
1908-recyclable-and-low-fat-products

Brainteaser

2481-strictly-palindromic-number
2503-longest-subarray-with-maximum-bitwise-and
2837-minimum-operations-to-make-the-integer-zero
3462-vowels-game-in-a-string

Ordered Set

2023-design-movie-rental-system
2429-design-a-food-rating-system
3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii
3678-design-task-manager
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii
3827-implement-router

Probability and Statistics

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

Game Theory

3462-vowels-game-in-a-string

Bitmask

3851-find-sum-of-array-product-of-magical-sequences

Bucket Sort

0451-sort-characters-by-frequency

Doubly-Linked List

3507-minimum-pair-removal-to-sort-array-i
3510-minimum-pair-removal-to-sort-array-ii