LeetCode

This repository contains a collection of LeetCode solutions I have worked on, categorized by topics and problem difficulty. It serves as a reference to track my progress in solving coding problems .

Array

0075-sort-colors
0330-patching-array
0442-find-all-duplicates-in-an-array
0502-ipo
0853-most-profit-assigning-work
0882-peak-index-in-a-mountain-array
0982-minimum-increment-to-make-array-unique
1138-grumpy-bookstore-owner
1605-minimum-number-of-days-to-make-m-bouquets
2148-minimum-number-of-moves-to-seat-everyone

Hash Table

0017-letter-combinations-of-a-phone-number
0141-linked-list-cycle
0142-linked-list-cycle-ii
0442-find-all-duplicates-in-an-array

Binary Search

0633-sum-of-square-numbers
0853-most-profit-assigning-work
0882-peak-index-in-a-mountain-array
1605-minimum-number-of-days-to-make-m-bouquets

Two Pointers

0075-sort-colors
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0344-reverse-string
0633-sum-of-square-numbers
0853-most-profit-assigning-work
0908-middle-of-the-linked-list

String

0017-letter-combinations-of-a-phone-number
0125-valid-palindrome
0344-reverse-string
2021-remove-all-occurrences-of-a-substring

Backtracking

0017-letter-combinations-of-a-phone-number

Sorting

0075-sort-colors
0502-ipo
0853-most-profit-assigning-work
0982-minimum-increment-to-make-array-unique
2148-minimum-number-of-moves-to-seat-everyone

Greedy

0330-patching-array
0502-ipo
0853-most-profit-assigning-work
0982-minimum-increment-to-make-array-unique
2148-minimum-number-of-moves-to-seat-everyone

Linked List

0025-reverse-nodes-in-k-group
0141-linked-list-cycle
0142-linked-list-cycle-ii
0206-reverse-linked-list
0908-middle-of-the-linked-list

Recursion

0025-reverse-nodes-in-k-group
0206-reverse-linked-list

Counting

0982-minimum-increment-to-make-array-unique

Heap (Priority Queue)

0502-ipo

Math

0633-sum-of-square-numbers

Sliding Window

1138-grumpy-bookstore-owner

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0046-permutations
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0063-unique-paths-ii
0064-minimum-path-sum
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0079-word-search
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0088-merge-sorted-array
0090-subsets-ii
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0128-longest-consecutive-sequence
0130-surrounded-regions
0134-gas-station
0136-single-number
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0188-best-time-to-buy-and-sell-stock-iv
0189-rotate-array
0198-house-robber
0204-count-primes
0213-house-robber-ii
0216-combination-sum-iii
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0238-product-of-array-except-self
0239-sliding-window-maximum
0268-missing-number
0283-move-zeroes
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0322-coin-change
0324-wiggle-sort-ii
0347-top-k-frequent-elements
0354-russian-doll-envelopes
0407-trapping-rain-water-ii
0416-partition-equal-subset-sum
0417-pacific-atlantic-water-flow
0435-non-overlapping-intervals
0455-assign-cookies
0462-minimum-moves-to-equal-array-elements-ii
0485-max-consecutive-ones
0494-target-sum
0496-next-greater-element-i
0503-next-greater-element-ii
0518-coin-change-ii
0525-contiguous-array
0540-single-element-in-a-sorted-array
0542-01-matrix
0560-subarray-sum-equals-k
0638-shopping-offers
0661-image-smoother
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0733-flood-fill
0735-asteroid-collision
0747-min-cost-climbing-stairs
0792-binary-search
0794-swim-in-rising-water
0870-magic-squares-in-grid
0914-random-point-in-non-overlapping-rectangles
0921-spiral-matrix-iii
0934-bitwise-ors-of-subarrays
0943-sum-of-subarray-minimums
0961-n-repeated-element-in-size-2n-array
0967-minimum-falling-path-sum
0994-rotting-oranges
0999-regions-cut-by-slashes
1019-squares-of-a-sorted-array
1036-rotting-oranges
1050-construct-binary-search-tree-from-preorder-traversal
1073-number-of-enclaves
1121-partition-array-for-maximum-sum
1171-shortest-path-in-binary-matrix
1370-count-number-of-nice-subarrays
1556-make-two-arrays-equal-by-reversing-subarrays
1612-avoid-flood-in-the-city
1615-range-sum-of-sorted-subarray-sums
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1669-minimum-cost-to-cut-a-stick
1753-path-with-minimum-effort
1929-concatenation-of-array
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2132-convert-1d-array-into-2d-array
2137-final-value-of-variable-after-performing-operations
2163-kth-distinct-string-in-an-array
2244-number-of-laser-beams-in-a-bank
2255-minimum-swaps-to-group-all-1s-together-ii
2392-successful-pairs-of-spells-and-potions
2436-make-array-zero-by-subtracting-equal-amounts
2661-smallest-missing-non-negative-integer-after-operations
2727-number-of-senior-citizens
3235-minimum-cost-to-convert-string-i
3252-count-the-number-of-incremovable-subarrays-i
3383-taking-maximum-energy-from-the-mystic-dungeon
3437-maximum-total-damage-with-spell-casting
3501-delete-nodes-from-linked-list-present-in-array
3581-the-two-sneaky-numbers-of-digitville
3616-make-array-elements-equal-to-zero
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
3794-find-the-minimum-amount-of-time-to-brew-potions
3851-find-sum-of-array-product-of-magical-sequences

Hash Table

0001-two-sum
0017-letter-combinations-of-a-phone-number
0049-group-anagrams
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0187-repeated-dna-sequences
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0299-bulls-and-cows
0347-top-k-frequent-elements
0496-next-greater-element-i
0525-contiguous-array
0560-subarray-sum-equals-k
0653-two-sum-iv-input-is-a-bst
0870-magic-squares-in-grid
0961-n-repeated-element-in-size-2n-array
0999-regions-cut-by-slashes
1370-count-number-of-nice-subarrays
1556-make-two-arrays-equal-by-reversing-subarrays
1612-avoid-flood-in-the-city
2163-kth-distinct-string-in-an-array
2174-next-greater-numerically-balanced-number
2436-make-array-zero-by-subtracting-equal-amounts
2661-smallest-missing-non-negative-integer-after-operations
3276-minimum-number-of-pushes-to-type-word-ii
3437-maximum-total-damage-with-spell-casting
3501-delete-nodes-from-linked-list-present-in-array
3581-the-two-sneaky-numbers-of-digitville

Math

0002-add-two-numbers
0009-palindrome-number
0029-divide-two-integers
0048-rotate-image
0050-powx-n
0062-unique-paths
0066-plus-one
0070-climbing-stairs
0168-excel-sheet-column-title
0189-rotate-array
0204-count-primes
0231-power-of-two
0268-missing-number
0273-integer-to-english-words
0371-sum-of-two-integers
0462-minimum-moves-to-equal-array-elements-ii
0870-magic-squares-in-grid
0914-random-point-in-non-overlapping-rectangles
1013-fibonacci-number
1370-count-number-of-nice-subarrays
1501-circle-and-rectangle-overlapping
1642-water-bottles
1817-calculate-money-in-leetcode-bank
1951-find-the-winner-of-the-circular-game
2050-count-good-numbers
2174-next-greater-numerically-balanced-number
2244-number-of-laser-beams-in-a-bank
2661-smallest-missing-non-negative-integer-after-operations
3336-water-bottles-ii
3581-the-two-sneaky-numbers-of-digitville
3676-smallest-number-with-all-set-bits
3768-check-if-digits-are-equal-in-string-after-operations-i
3851-find-sum-of-array-product-of-magical-sequences

Sliding Window

0187-repeated-dna-sequences
0219-contains-duplicate-ii
0239-sliding-window-maximum
1370-count-number-of-nice-subarrays
2255-minimum-swaps-to-group-all-1s-together-ii
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii

Greedy

0011-container-with-most-water
0044-wildcard-matching
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0324-wiggle-sort-ii
0402-remove-k-digits
0435-non-overlapping-intervals
0455-assign-cookies
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
1612-avoid-flood-in-the-city
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
2436-make-array-zero-by-subtracting-equal-amounts
2661-smallest-missing-non-negative-integer-after-operations
3276-minimum-number-of-pushes-to-type-word-ii
3620-maximum-number-of-distinct-elements-after-operations

Sorting

0015-3sum
0016-3sum-closest
0018-4sum
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0324-wiggle-sort-ii
0347-top-k-frequent-elements
0354-russian-doll-envelopes
0435-non-overlapping-intervals
0455-assign-cookies
0462-minimum-moves-to-equal-array-elements-ii
1019-squares-of-a-sorted-array
1556-make-two-arrays-equal-by-reversing-subarrays
1615-range-sum-of-sorted-subarray-sums
1669-minimum-cost-to-cut-a-stick
2392-successful-pairs-of-spells-and-potions
2436-make-array-zero-by-subtracting-equal-amounts
3276-minimum-number-of-pushes-to-type-word-ii
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

Heap (Priority Queue)

0239-sliding-window-maximum
0347-top-k-frequent-elements
0407-trapping-rain-water-ii
0794-swim-in-rising-water
0803-cheapest-flights-within-k-stops
1612-avoid-flood-in-the-city
1753-path-with-minimum-effort
2436-make-array-zero-by-subtracting-equal-amounts

Simulation

0054-spiral-matrix
0735-asteroid-collision
0921-spiral-matrix-iii
1642-water-bottles
1929-concatenation-of-array
1951-find-the-winner-of-the-circular-game
2006-find-the-student-that-will-replace-the-chalk
2132-convert-1d-array-into-2d-array
2137-final-value-of-variable-after-performing-operations
2436-make-array-zero-by-subtracting-equal-amounts
3336-water-bottles-ii
3616-make-array-elements-equal-to-zero
3768-check-if-digits-are-equal-in-string-after-operations-i
3794-find-the-minimum-amount-of-time-to-brew-potions

String

0005-longest-palindromic-substring
0008-string-to-integer-atoi
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0044-wildcard-matching
0049-group-anagrams
0072-edit-distance
0079-word-search
0091-decode-ways
0115-distinct-subsequences
0131-palindrome-partitioning
0132-palindrome-partitioning-ii
0168-excel-sheet-column-title
0187-repeated-dna-sequences
0242-valid-anagram
0273-integer-to-english-words
0299-bulls-and-cows
0344-reverse-string
0402-remove-k-digits
0516-longest-palindromic-subsequence
0583-delete-operation-for-two-strings
0647-palindromic-substrings
1078-remove-outermost-parentheses
1170-shortest-common-supersequence
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1747-lexicographically-smallest-string-after-applying-operations
2130-maximum-product-of-the-length-of-two-palindromic-subsequences
2137-final-value-of-variable-after-performing-operations
2163-kth-distinct-string-in-an-array
2244-number-of-laser-beams-in-a-bank
2727-number-of-senior-citizens
3233-maximize-the-number-of-partitions-after-operations
3235-minimum-cost-to-convert-string-i
3276-minimum-number-of-pushes-to-type-word-ii
3768-check-if-digits-are-equal-in-string-after-operations-i

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0016-3sum-closest
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0344-reverse-string
0455-assign-cookies
0647-palindromic-substrings
0653-two-sum-iv-input-is-a-bst
0908-middle-of-the-linked-list
1019-squares-of-a-sorted-array
1615-range-sum-of-sorted-subarray-sums
2216-delete-the-middle-node-of-a-linked-list
2392-successful-pairs-of-spells-and-potions
3252-count-the-number-of-incremovable-subarrays-i
3437-maximum-total-damage-with-spell-casting

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
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0222-count-complete-tree-nodes
0268-missing-number
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0354-russian-doll-envelopes
0540-single-element-in-a-sorted-array
0792-binary-search
0794-swim-in-rising-water
0914-random-point-in-non-overlapping-rectangles
1612-avoid-flood-in-the-city
1615-range-sum-of-sorted-subarray-sums
1753-path-with-minimum-effort
2006-find-the-student-that-will-replace-the-chalk
2392-successful-pairs-of-spells-and-potions
3252-count-the-number-of-incremovable-subarrays-i
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

Counting

0169-majority-element
0229-majority-element-ii
0299-bulls-and-cows
0347-top-k-frequent-elements
2163-kth-distinct-string-in-an-array
2174-next-greater-numerically-balanced-number
3276-minimum-number-of-pushes-to-type-word-ii
3437-maximum-total-damage-with-spell-casting

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0044-wildcard-matching
0050-powx-n
0143-reorder-list
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0273-integer-to-english-words
1013-fibonacci-number
1951-find-the-winner-of-the-circular-game
2050-count-good-numbers

Matrix

0048-rotate-image
0054-spiral-matrix
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0085-maximal-rectangle
0130-surrounded-regions
0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0542-01-matrix
0661-image-smoother
0733-flood-fill
0794-swim-in-rising-water
0870-magic-squares-in-grid
0921-spiral-matrix-iii
0967-minimum-falling-path-sum
0994-rotting-oranges
0999-regions-cut-by-slashes
1036-rotting-oranges
1073-number-of-enclaves
1171-shortest-path-in-binary-matrix
1753-path-with-minimum-effort
2132-convert-1d-array-into-2d-array
2244-number-of-laser-beams-in-a-bank

Depth-First Search

0079-word-search
0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0130-surrounded-regions
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0417-pacific-atlantic-water-flow
0543-diameter-of-binary-tree
0547-number-of-provinces
0572-subtree-of-another-tree
0653-two-sum-iv-input-is-a-bst
0733-flood-fill
0794-swim-in-rising-water
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0999-regions-cut-by-slashes
1073-number-of-enclaves
1747-lexicographically-smallest-string-after-applying-operations
1753-path-with-minimum-effort

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0130-surrounded-regions
0199-binary-tree-right-side-view
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0322-coin-change
0407-trapping-rain-water-ii
0417-pacific-atlantic-water-flow
0542-01-matrix
0547-number-of-provinces
0653-two-sum-iv-input-is-a-bst
0733-flood-fill
0794-swim-in-rising-water
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0994-rotting-oranges
0999-regions-cut-by-slashes
1036-rotting-oranges
1073-number-of-enclaves
1171-shortest-path-in-binary-matrix
1747-lexicographically-smallest-string-after-applying-operations
1753-path-with-minimum-effort

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions
0547-number-of-provinces
0794-swim-in-rising-water
0801-is-graph-bipartite
0999-regions-cut-by-slashes
1073-number-of-enclaves
1753-path-with-minimum-effort

Prefix Sum

0238-product-of-array-except-self
0525-contiguous-array
0560-subarray-sum-equals-k
0914-random-point-in-non-overlapping-rectangles
1370-count-number-of-nice-subarrays
2006-find-the-student-that-will-replace-the-chalk
3383-taking-maximum-energy-from-the-mystic-dungeon
3616-make-array-elements-equal-to-zero
3622-maximum-frequency-of-an-element-after-performing-operations-i
3640-maximum-frequency-of-an-element-after-performing-operations-ii
3794-find-the-minimum-amount-of-time-to-brew-potions

Enumeration

0204-count-primes
1747-lexicographically-smallest-string-after-applying-operations
2174-next-greater-numerically-balanced-number
3252-count-the-number-of-incremovable-subarrays-i

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0044-wildcard-matching
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0085-maximal-rectangle
0091-decode-ways
0115-distinct-subsequences
0118-pascals-triangle
0120-triangle
0121-best-time-to-buy-and-sell-stock
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
0132-palindrome-partitioning-ii
0152-maximum-product-subarray
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0213-house-robber-ii
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0312-burst-balloons
0322-coin-change
0338-counting-bits
0354-russian-doll-envelopes
0416-partition-equal-subset-sum
0435-non-overlapping-intervals
0494-target-sum
0516-longest-palindromic-subsequence
0518-coin-change-ii
0542-01-matrix
0583-delete-operation-for-two-strings
0638-shopping-offers
0647-palindromic-substrings
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0747-min-cost-climbing-stairs
0803-cheapest-flights-within-k-stops
0934-bitwise-ors-of-subarrays
0943-sum-of-subarray-minimums
0967-minimum-falling-path-sum
1013-fibonacci-number
1121-partition-array-for-maximum-sum
1170-shortest-common-supersequence
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array
1669-minimum-cost-to-cut-a-stick
2090-number-of-ways-to-arrive-at-destination
2130-maximum-product-of-the-length-of-two-palindromic-subsequences
3233-maximize-the-number-of-partitions-after-operations
3437-maximum-total-damage-with-spell-casting
3851-find-sum-of-array-product-of-magical-sequences

Geometry

1501-circle-and-rectangle-overlapping

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
1951-find-the-winner-of-the-circular-game

Reservoir Sampling

0914-random-point-in-non-overlapping-rectangles

Ordered Set

0914-random-point-in-non-overlapping-rectangles

Randomized

0914-random-point-in-non-overlapping-rectangles

Bit Manipulation

0029-divide-two-integers
0078-subsets
0090-subsets-ii
0136-single-number
0187-repeated-dna-sequences
0190-reverse-bits
0191-number-of-1-bits
0222-count-complete-tree-nodes
0231-power-of-two
0268-missing-number
0287-find-the-duplicate-number
0338-counting-bits
0371-sum-of-two-integers
0638-shopping-offers
0934-bitwise-ors-of-subarrays
2130-maximum-product-of-the-length-of-two-palindromic-subsequences
2323-minimum-bit-flips-to-convert-number
3233-maximize-the-number-of-partitions-after-operations
3676-smallest-number-with-all-set-bits
3851-find-sum-of-array-product-of-magical-sequences

Rolling Hash

0187-repeated-dna-sequences

Hash Function

0187-repeated-dna-sequences
0572-subtree-of-another-tree

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0078-subsets
0079-word-search
0090-subsets-ii
0131-palindrome-partitioning
0216-combination-sum-iii
0494-target-sum
0638-shopping-offers
2130-maximum-product-of-the-length-of-two-palindromic-subsequences
2174-next-greater-numerically-balanced-number

Bitmask

0638-shopping-offers
2130-maximum-product-of-the-length-of-two-palindromic-subsequences
3233-maximize-the-number-of-partitions-after-operations
3851-find-sum-of-array-product-of-magical-sequences

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0324-wiggle-sort-ii
0347-top-k-frequent-elements

Quickselect

0324-wiggle-sort-ii
0347-top-k-frequent-elements

Memoization

0070-climbing-stairs
0638-shopping-offers
1013-fibonacci-number

Graph

0207-course-schedule
0210-course-schedule-ii
0547-number-of-provinces
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2090-number-of-ways-to-arrive-at-destination
3235-minimum-cost-to-convert-string-i

Shortest Path

0803-cheapest-flights-within-k-stops
1456-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
2090-number-of-ways-to-arrive-at-destination
3235-minimum-cost-to-convert-string-i

Bucket Sort

0347-top-k-frequent-elements

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0085-maximal-rectangle
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0143-reorder-list
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
0173-binary-search-tree-iterator
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
0735-asteroid-collision
0937-online-stock-span
0943-sum-of-subarray-minimums
1050-construct-binary-search-tree-from-preorder-traversal
1078-remove-outermost-parentheses
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array

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
0937-online-stock-span
0943-sum-of-subarray-minimums
1050-construct-binary-search-tree-from-preorder-traversal
1633-minimum-number-of-increments-on-subarrays-to-form-a-target-array

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0061-rotate-list
0114-flatten-binary-tree-to-linked-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-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
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list
3501-delete-nodes-from-linked-list-present-in-array

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0653-two-sum-iv-input-is-a-bst
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0099-recover-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0173-binary-search-tree-iterator
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0226-invert-binary-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0450-delete-node-in-a-bst
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0653-two-sum-iv-input-is-a-bst
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal

Combinatorics

0062-unique-paths
3768-check-if-digits-are-equal-in-string-after-operations-i
3851-find-sum-of-array-product-of-magical-sequences

Design

0155-min-stack
0173-binary-search-tree-iterator
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0937-online-stock-span

Data Stream

0937-online-stock-span

Monotonic Queue

0239-sliding-window-maximum

Binary Search Tree

0098-validate-binary-search-tree
0099-recover-binary-search-tree
0173-binary-search-tree-iterator
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0450-delete-node-in-a-bst
0653-two-sum-iv-input-is-a-bst
0784-insert-into-a-binary-search-tree
1050-construct-binary-search-tree-from-preorder-traversal

Iterator

0173-binary-search-tree-iterator

Topological Sort

0207-course-schedule
0210-course-schedule-ii
2090-number-of-ways-to-arrive-at-destination

Number Theory

0204-count-primes
3768-check-if-digits-are-equal-in-string-after-operations-i

Database

0180-consecutive-numbers
0197-rising-temperature
0570-managers-with-at-least-5-direct-reports
0595-big-countries
0626-exchange-seats
1135-customers-who-bought-all-products
1153-product-sales-analysis-i
1155-product-sales-analysis-iii
1182-game-play-analysis-iv
1278-product-price-at-a-given-date
1327-last-person-to-fit-in-the-bus
1390-average-selling-price
1480-movie-rating
1827-invalid-tweets
2057-count-salary-categories
2087-confirmation-rate
2127-employees-whose-manager-left-the-company

String Matching

0572-subtree-of-another-tree

Union-Find

0130-surrounded-regions