LeetCode

LeetCode Topics

Array

0011-container-with-most-water
0036-valid-sudoku
0037-sudoku-solver
0118-pascals-triangle
0322-coin-change
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0498-diagonal-traverse
0594-longest-harmonious-subsequence
0854-making-a-large-island
0905-length-of-longest-fibonacci-subsequence
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0934-bitwise-ors-of-subarrays
0940-fruit-into-baskets
1006-vowel-spellchecker
1335-maximum-candies-allocated-to-k-children
1350-remove-sub-folders-from-the-filesystem
1353-find-resultant-array-after-removing-anagrams
1364-tuple-with-same-product
1396-count-servers-that-communicate
1426-find-n-unique-integers-sum-up-to-zero
1477-product-of-the-last-k-numbers
1478-maximum-number-of-events-that-can-be-attended
1510-find-lucky-integer-in-an-array
1586-longest-subarray-of-1s-after-deleting-one-element
1612-avoid-flood-in-the-city
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
1628-count-submatrices-with-all-ones
1631-number-of-sub-arrays-with-odd-sum
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1813-maximum-erasure-value
1819-construct-the-lexicographically-largest-valid-sequence
1849-maximum-absolute-sum-of-any-subarray
1878-check-if-array-is-sorted-and-rotated
1917-maximum-average-pass-ratio
1995-finding-pairs-with-a-certain-sum
2079-delete-duplicate-folders-in-system
2107-find-unique-binary-string
2137-final-value-of-variable-after-performing-operations
2170-count-number-of-maximum-bitwise-or-subsets
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
2307-replace-non-coprime-numbers-in-array
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2320-find-all-k-distant-indices-in-an-array
2400-minimum-score-after-removals-on-a-tree
2429-design-a-food-rating-system
2432-number-of-zero-filled-subarrays
2448-count-number-of-bad-pairs
2478-longest-nice-subarray
2479-meeting-rooms-iii
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
2614-maximum-count-of-positive-integer-and-negative-integer
2661-smallest-missing-non-negative-integer-after-operations
2665-minimum-time-to-repair-cars
2681-put-marbles-in-bags
2685-first-completely-painted-row-or-column
2689-rearranging-fruits
2690-house-robber-iv
2707-merge-two-2d-arrays-by-summing-values
2764-maximum-number-of-fish-in-a-grid
3001-apply-operations-to-maximize-score
3152-maximum-value-of-an-ordered-triplet-ii
3154-maximum-value-of-an-ordered-triplet-i
3219-make-lexicographically-smallest-array-by-swapping-elements
3227-find-missing-and-repeated-values
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
3348-minimum-cost-walk-in-weighted-graph
3372-longest-strictly-increasing-or-strictly-decreasing-subarray
3383-taking-maximum-energy-from-the-mystic-dungeon
3429-special-array-i
3430-count-days-without-meetings
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
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3483-alternating-groups-ii
3612-adjacent-increasing-subarrays-detection-i
3619-adjacent-increasing-subarrays-detection-ii
3620-maximum-number-of-distinct-elements-after-operations
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii
3643-zero-array-transformation-ii
3648-find-the-maximum-number-of-fruits-collected
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
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
3851-find-sum-of-array-product-of-magical-sequences

Depth-First Search

0417-pacific-atlantic-water-flow
0684-redundant-connection
0820-find-eventual-safe-states
0854-making-a-large-island
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1350-remove-sub-folders-from-the-filesystem
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1558-course-schedule-iv
1747-lexicographically-smallest-string-after-applying-operations
2246-maximum-employees-to-be-invited-to-a-meeting
2400-minimum-score-after-removals-on-a-tree
2438-find-closest-node-to-given-two-nodes
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components

Breadth-First Search

0322-coin-change
0417-pacific-atlantic-water-flow
0684-redundant-connection
0820-find-eventual-safe-states
0854-making-a-large-island
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
1396-count-servers-that-communicate
1558-course-schedule-iv
1747-lexicographically-smallest-string-after-applying-operations
2583-divide-nodes-into-the-maximum-number-of-groups
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components

Union Find

0684-redundant-connection
0854-making-a-large-island
1396-count-servers-that-communicate
2583-divide-nodes-into-the-maximum-number-of-groups
2764-maximum-number-of-fish-in-a-grid
2793-count-the-number-of-complete-components
3219-make-lexicographically-smallest-array-by-swapping-elements
3348-minimum-cost-walk-in-weighted-graph

Matrix

0036-valid-sudoku
0037-sudoku-solver
0417-pacific-atlantic-water-flow
0498-diagonal-traverse
0854-making-a-large-island
1396-count-servers-that-communicate
1628-count-submatrices-with-all-ones
2685-first-completely-painted-row-or-column
2764-maximum-number-of-fish-in-a-grid
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

Counting

0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1160-letter-tile-possibilities
1364-tuple-with-same-product
1396-count-servers-that-communicate
1510-find-lucky-integer-in-an-array
2140-longest-subsequence-repeated-k-times
2308-divide-array-into-equal-pairs
2448-count-number-of-bad-pairs
2614-maximum-count-of-positive-integer-and-negative-integer
3437-maximum-total-damage-with-spell-casting
3872-find-most-frequent-vowel-and-consonant

Graph

0684-redundant-connection
0820-find-eventual-safe-states
1558-course-schedule-iv
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
2246-maximum-employees-to-be-invited-to-a-meeting
2438-find-closest-node-to-given-two-nodes
2583-divide-nodes-into-the-maximum-number-of-groups
2793-count-the-number-of-complete-components
3348-minimum-cost-walk-in-weighted-graph

Topological Sort

0820-find-eventual-safe-states
1558-course-schedule-iv
2090-number-of-ways-to-arrive-at-destination
2220-find-all-possible-recipes-from-given-supplies
2246-maximum-employees-to-be-invited-to-a-meeting

Sorting

0368-largest-divisible-subset
0594-longest-harmonious-subsequence
0900-reordered-power-of-2
1353-find-resultant-array-after-removing-anagrams
1478-maximum-number-of-events-that-can-be-attended
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2479-meeting-rooms-iii
2497-maximum-matching-of-players-with-trainers
2681-put-marbles-in-bags
2689-rearranging-fruits
3001-apply-operations-to-maximize-score
3219-make-lexicographically-smallest-array-by-swapping-elements
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
3620-maximum-number-of-distinct-elements-after-operations
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii
3657-check-if-grid-can-be-cut-into-sections
3748-sort-matrix-by-diagonals

Dynamic Programming

0118-pascals-triangle
0322-coin-change
0368-largest-divisible-subset
0416-partition-equal-subset-sum
0826-soup-servings
0867-new-21-game
0905-length-of-longest-fibonacci-subsequence
0934-bitwise-ors-of-subarrays
1170-shortest-common-supersequence
1586-longest-subarray-of-1s-after-deleting-one-element
1628-count-submatrices-with-all-ones
1631-number-of-sub-arrays-with-odd-sum
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1849-maximum-absolute-sum-of-any-subarray
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
3233-maximize-the-number-of-partitions-after-operations
3437-maximum-total-damage-with-spell-casting
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

Hash Table

0036-valid-sudoku
0037-sudoku-solver
0594-longest-harmonious-subsequence
0768-partition-labels
0900-reordered-power-of-2
0905-length-of-longest-fibonacci-subsequence
0925-construct-binary-tree-from-preorder-and-postorder-traversal
0940-fruit-into-baskets
1006-vowel-spellchecker
1160-letter-tile-possibilities
1218-lowest-common-ancestor-of-deepest-leaves
1264-maximum-number-of-words-you-can-type
1353-find-resultant-array-after-removing-anagrams
1364-tuple-with-same-product
1387-find-elements-in-a-contaminated-binary-tree
1460-number-of-substrings-containing-all-three-characters
1510-find-lucky-integer-in-an-array
1612-avoid-flood-in-the-city
1813-maximum-erasure-value
1995-finding-pairs-with-a-certain-sum
2079-delete-duplicate-folders-in-system
2107-find-unique-binary-string
2220-find-all-possible-recipes-from-given-supplies
2308-divide-array-into-equal-pairs
2429-design-a-food-rating-system
2448-count-number-of-bad-pairs
2479-meeting-rooms-iii
2661-smallest-missing-non-negative-integer-after-operations
2685-first-completely-painted-row-or-column
2689-rearranging-fruits
2707-merge-two-2d-arrays-by-summing-values
3227-find-missing-and-repeated-values
3437-maximum-total-damage-with-spell-casting
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3788-maximum-unique-subarray-sum-after-deletion
3872-find-most-frequent-vowel-and-consonant

String

0768-partition-labels
1006-vowel-spellchecker
1093-recover-a-tree-from-preorder-traversal
1160-letter-tile-possibilities
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
1353-find-resultant-array-after-removing-anagrams
1460-number-of-substrings-containing-all-three-characters
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1744-number-of-ways-to-form-a-target-string-given-a-dictionary
1747-lexicographically-smallest-string-after-applying-operations
1818-maximum-score-from-removing-substrings
2021-remove-all-occurrences-of-a-substring
2079-delete-duplicate-folders-in-system
2107-find-unique-binary-string
2137-final-value-of-variable-after-performing-operations
2140-longest-subsequence-repeated-k-times
2220-find-all-possible-recipes-from-given-supplies
2346-largest-3-same-digit-number-in-string
2429-design-a-food-rating-system
2456-construct-smallest-number-from-di-string
2463-minimum-recolors-to-get-k-consecutive-black-blocks
3233-maximize-the-number-of-partitions-after-operations
3396-valid-word
3447-clear-digits
3462-vowels-game-in-a-string
3569-count-of-substrings-containing-every-vowel-and-k-consonants-ii
3872-find-most-frequent-vowel-and-consonant

Math

0231-power-of-two
0326-power-of-three
0342-power-of-four
0368-largest-divisible-subset
0826-soup-servings
0867-new-21-game
0900-reordered-power-of-2
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
1477-product-of-the-last-k-numbers
1631-number-of-sub-arrays-with-odd-sum
1817-calculate-money-in-leetcode-bank
1889-check-if-number-is-a-sum-of-powers-of-three
2307-replace-non-coprime-numbers-in-array
2432-number-of-zero-filled-subarrays
2448-count-number-of-bad-pairs
2610-closest-prime-numbers-in-range
2649-count-total-number-of-colored-cells
2661-smallest-missing-non-negative-integer-after-operations
2802-find-the-punishment-number-of-an-integer
3001-apply-operations-to-maximize-score
3227-find-missing-and-repeated-values
3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i
3462-vowels-game-in-a-string
3600-find-the-k-th-character-in-string-game-i
3744-minimum-operations-to-make-array-elements-zero
3830-find-closest-person
3851-find-sum-of-array-product-of-magical-sequences

Design

1387-find-elements-in-a-contaminated-binary-tree
1477-product-of-the-last-k-numbers
1995-finding-pairs-with-a-certain-sum
2429-design-a-food-rating-system

Data Stream

1477-product-of-the-last-k-numbers

Prefix Sum

1477-product-of-the-last-k-numbers
1631-number-of-sub-arrays-with-odd-sum
2229-maximum-fruits-harvested-after-at-most-k-steps
2529-range-product-queries-of-powers
3383-taking-maximum-energy-from-the-mystic-dungeon
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii
3643-zero-array-transformation-ii
3789-maximize-subarrays-after-removing-one-conflicting-pair
3794-find-the-minimum-amount-of-time-to-brew-potions

Stack

1628-count-submatrices-with-all-ones
1818-maximum-score-from-removing-substrings
2021-remove-all-occurrences-of-a-substring
2307-replace-non-coprime-numbers-in-array
2456-construct-smallest-number-from-di-string
3001-apply-operations-to-maximize-score
3447-clear-digits

Simulation

0498-diagonal-traverse
2021-remove-all-occurrences-of-a-substring
2137-final-value-of-variable-after-performing-operations
2265-partition-array-according-to-given-pivot
2408-number-of-people-aware-of-a-secret
2479-meeting-rooms-iii
2551-apply-operations-to-an-array
3447-clear-digits
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

Backtracking

0037-sudoku-solver
1160-letter-tile-possibilities
1516-the-k-th-lexicographical-string-of-all-happy-strings-of-length-n
1819-construct-the-lexicographically-largest-valid-sequence
2107-find-unique-binary-string
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets
2456-construct-smallest-number-from-di-string
2802-find-the-punishment-number-of-an-integer

Greedy

0011-container-with-most-water
0768-partition-labels
1448-maximum-69-number
1478-maximum-number-of-events-that-can-be-attended
1612-avoid-flood-in-the-city
1818-maximum-score-from-removing-substrings
1917-maximum-average-pass-ratio
2140-longest-subsequence-repeated-k-times
2456-construct-smallest-number-from-di-string
2497-maximum-matching-of-players-with-trainers
2661-smallest-missing-non-negative-integer-after-operations
2681-put-marbles-in-bags
2689-rearranging-fruits
3001-apply-operations-to-maximize-score
3620-maximum-number-of-distinct-elements-after-operations
3741-reschedule-meetings-for-maximum-free-time-ii
3743-reschedule-meetings-for-maximum-free-time-i
3788-maximum-unique-subarray-sum-after-deletion

Tree

0925-construct-binary-tree-from-preorder-and-postorder-traversal
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree
2400-minimum-score-after-removals-on-a-tree

Binary Tree

0925-construct-binary-tree-from-preorder-and-postorder-traversal
1093-recover-a-tree-from-preorder-traversal
1218-lowest-common-ancestor-of-deepest-leaves
1387-find-elements-in-a-contaminated-binary-tree

Divide and Conquer

0925-construct-binary-tree-from-preorder-and-postorder-traversal

Two Pointers

0011-container-with-most-water
0768-partition-labels
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
2265-partition-array-according-to-given-pivot
2320-find-all-k-distant-indices-in-an-array
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array
2707-merge-two-2d-arrays-by-summing-values
3437-maximum-total-damage-with-spell-casting

Number Theory

2307-replace-non-coprime-numbers-in-array
2610-closest-prime-numbers-in-range
3001-apply-operations-to-maximize-score

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
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
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
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii
3743-reschedule-meetings-for-maximum-free-time-i

Binary Search

1335-maximum-candies-allocated-to-k-children
1612-avoid-flood-in-the-city
1621-number-of-subsequences-that-satisfy-the-given-sum-condition
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
3619-adjacent-increasing-subarrays-detection-ii
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii
3643-zero-array-transformation-ii
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Bit Manipulation

0231-power-of-two
0342-power-of-four
0934-bitwise-ors-of-subarrays
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
3233-maximize-the-number-of-partitions-after-operations
3348-minimum-cost-walk-in-weighted-graph
3475-minimum-operations-to-make-binary-array-elements-equal-to-one-i
3600-find-the-k-th-character-in-string-game-i
3744-minimum-operations-to-make-array-elements-zero
3851-find-sum-of-array-product-of-magical-sequences

Queue

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

Shortest Path

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

Monotonic Stack

1628-count-submatrices-with-all-ones
3001-apply-operations-to-maximize-score

Heap (Priority Queue)

1478-maximum-number-of-events-that-can-be-attended
1612-avoid-flood-in-the-city
1917-maximum-average-pass-ratio
2267-minimum-difference-in-sums-after-removal-of-elements
2429-design-a-food-rating-system
2479-meeting-rooms-iii
2681-put-marbles-in-bags

Enumeration

0900-reordered-power-of-2
1747-lexicographically-smallest-string-after-applying-operations
2140-longest-subsequence-repeated-k-times
2170-count-number-of-maximum-bitwise-or-subsets
2837-minimum-operations-to-make-the-integer-zero
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

Recursion

0231-power-of-two
0326-power-of-three
0342-power-of-four
3600-find-the-k-th-character-in-string-game-i

Memoization

2028-the-earliest-and-latest-rounds-where-players-compete
3733-length-of-longest-v-shaped-diagonal-segment

Linked List

1411-convert-binary-number-in-a-linked-list-to-integer

Trie

1350-remove-sub-folders-from-the-filesystem
2079-delete-duplicate-folders-in-system

Hash Function

2079-delete-duplicate-folders-in-system

Segment Tree

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

Brainteaser

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

Ordered Set

2429-design-a-food-rating-system
3790-fruits-into-baskets-ii
3791-fruits-into-baskets-iii

Probability and Statistics

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

Geometry

3277-find-the-number-of-ways-to-place-people-ii
3278-find-the-number-of-ways-to-place-people-i

Game Theory

3462-vowels-game-in-a-string

Combinatorics

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

Bitmask

3233-maximize-the-number-of-partitions-after-operations
3851-find-sum-of-array-product-of-magical-sequences