LeetCode-Questions

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

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
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
0041-first-missing-positive
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0048-rotate-image
0049-group-anagrams
0053-maximum-subarray
0055-jump-game
0056-merge-intervals
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
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0090-subsets-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0118-pascals-triangle
0119-pascals-triangle-ii
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
0135-candy
0136-single-number
0137-single-number-ii
0150-evaluate-reverse-polish-notation
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0188-best-time-to-buy-and-sell-stock-iv
0198-house-robber
0200-number-of-islands
0204-count-primes
0209-minimum-size-subarray-sum
0213-house-robber-ii
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0219-contains-duplicate-ii
0228-summary-ranges
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
0322-coin-change
0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
0399-evaluate-division
0417-pacific-atlantic-water-flow
0421-maximum-xor-of-two-numbers-in-an-array
0435-non-overlapping-intervals
0448-find-all-numbers-disappeared-in-an-array
0452-minimum-number-of-arrows-to-burst-balloons
0485-max-consecutive-ones
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0575-distribute-candies
0611-valid-triangle-number
0628-maximum-product-of-three-numbers
0695-max-area-of-island
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0721-accounts-merge
0733-flood-fill
0739-daily-temperatures
0745-find-smallest-letter-greater-than-target
0792-binary-search
0817-design-hashmap
0853-most-profit-assigning-work
0882-peak-index-in-a-mountain-array
0907-koko-eating-bananas
1014-k-closest-points-to-origin
1032-satisfiability-of-equality-equations
1036-rotting-oranges
1047-maximize-sum-of-array-after-k-negations
1050-construct-binary-search-tree-from-preorder-traversal
1056-capacity-to-ship-packages-within-d-days
1073-number-of-enclaves
1127-last-stone-weight
1185-find-in-mountain-array
1325-path-with-maximum-probability
1353-find-resultant-array-after-removing-anagrams
1378-cells-with-odd-values-in-a-matrix
1380-number-of-closed-islands
1396-count-servers-that-communicate
1580-shuffle-the-array
1603-running-sum-of-1d-array
1730-special-array-with-x-elements-greater-than-or-equal-x
1753-path-with-minimum-effort
1757-minimum-jumps-to-reach-home
1843-number-of-rectangles-that-can-form-the-largest-square
1966-frequency-of-the-most-frequent-element
2048-build-array-from-permutation
2058-concatenation-of-array
2117-find-original-array-from-doubled-array
2210-find-target-indices-after-sorting-array
2359-maximum-white-tiles-covered-by-a-carpet
2640-maximum-number-of-integers-to-choose-from-a-range-i
2698-find-the-array-concatenation-value
3329-find-the-length-of-the-longest-common-prefix
3732-calculate-score-after-performing-instructions

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0037-sudoku-solver
0041-first-missing-positive
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0128-longest-consecutive-sequence
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0208-implement-trie-prefix-tree
0217-contains-duplicate
0219-contains-duplicate-ii
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0421-maximum-xor-of-two-numbers-in-an-array
0448-find-all-numbers-disappeared-in-an-array
0560-subarray-sum-equals-k
0575-distribute-candies
0653-two-sum-iv-input-is-a-bst
0721-accounts-merge
0817-design-hashmap
1353-find-resultant-array-after-removing-anagrams
2117-find-original-array-from-doubled-array
2640-maximum-number-of-integers-to-choose-from-a-range-i
3329-find-the-length-of-the-longest-common-prefix
3732-calculate-score-after-performing-instructions

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0061-rotate-list
0092-reverse-linked-list-ii
0114-flatten-binary-tree-to-linked-list
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0146-lru-cache
0147-insertion-sort-list
0148-sort-list
0160-intersection-of-two-linked-lists
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0528-swapping-nodes-in-a-linked-list
0817-design-hashmap
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer

Math

0002-add-two-numbers
0007-reverse-integer
0009-palindrome-number
0048-rotate-image
0050-powx-n
0060-permutation-sequence
0062-unique-paths
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0204-count-primes
0231-power-of-two
0268-missing-number
0279-perfect-squares
0326-power-of-three
0342-power-of-four
0367-valid-perfect-square
0628-maximum-product-of-three-numbers
0903-implement-rand10-using-rand7
1013-fibonacci-number
1014-k-closest-points-to-origin
1378-cells-with-odd-values-in-a-matrix
1411-convert-binary-number-in-a-linked-list-to-integer

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0025-reverse-nodes-in-k-group
0050-powx-n
0060-permutation-sequence
0143-reorder-list
0203-remove-linked-list-elements
0206-reverse-linked-list
0231-power-of-two
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four
1013-fibonacci-number

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
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0268-missing-number
0278-first-bad-version
0287-find-the-duplicate-number
0300-longest-increasing-subsequence
0367-valid-perfect-square
0374-guess-number-higher-or-lower
0540-single-element-in-a-sorted-array
0611-valid-triangle-number
0745-find-smallest-letter-greater-than-target
0792-binary-search
0853-most-profit-assigning-work
0882-peak-index-in-a-mountain-array
0907-koko-eating-bananas
1056-capacity-to-ship-packages-within-d-days
1185-find-in-mountain-array
1730-special-array-with-x-elements-greater-than-or-equal-x
1753-path-with-minimum-effort
1966-frequency-of-the-most-frequent-element
2210-find-target-indices-after-sorting-array
2359-maximum-white-tiles-covered-by-a-carpet
2640-maximum-number-of-integers-to-choose-from-a-range-i

Divide and Conquer

0004-median-of-two-sorted-arrays
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin
1285-balance-a-binary-search-tree

Matrix

0037-sudoku-solver
0048-rotate-image
0063-unique-paths-ii
0064-minimum-path-sum
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0130-surrounded-regions
0200-number-of-islands
0417-pacific-atlantic-water-flow
0695-max-area-of-island
0733-flood-fill
1036-rotting-oranges
1073-number-of-enclaves
1380-number-of-closed-islands
1396-count-servers-that-communicate
1753-path-with-minimum-effort

Dynamic Programming

0032-longest-valid-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0072-edit-distance
0091-decode-ways
0118-pascals-triangle
0119-pascals-triangle-ii
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
0279-perfect-squares
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0322-coin-change
0392-is-subsequence
0435-non-overlapping-intervals
0516-longest-palindromic-subsequence
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0803-cheapest-flights-within-k-stops
1013-fibonacci-number
1250-longest-common-subsequence
1437-minimum-insertion-steps-to-make-a-string-palindrome
1757-minimum-jumps-to-reach-home

Two Pointers

0011-container-with-most-water
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
0061-rotate-list
0075-sort-colors
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0143-reorder-list
0148-sort-list
0160-intersection-of-two-linked-lists
0167-two-sum-ii-input-array-is-sorted
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0295-find-median-from-data-stream
0392-is-subsequence
0528-swapping-nodes-in-a-linked-list
0611-valid-triangle-number
0653-two-sum-iv-input-is-a-bst
0853-most-profit-assigning-work
0908-middle-of-the-linked-list
2698-find-the-array-concatenation-value

Sorting

0015-3sum
0018-4sum
0047-permutations-ii
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0147-insertion-sort-list
0148-sort-list
0169-majority-element
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
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0611-valid-triangle-number
0628-maximum-product-of-three-numbers
0721-accounts-merge
0853-most-profit-assigning-work
1014-k-closest-points-to-origin
1047-maximize-sum-of-array-after-k-negations
1353-find-resultant-array-after-removing-anagrams
1427-all-elements-in-two-binary-search-trees
1730-special-array-with-x-elements-greater-than-or-equal-x
1966-frequency-of-the-most-frequent-element
1970-sorting-the-sentence
2117-find-original-array-from-doubled-array
2210-find-target-indices-after-sorting-array
2359-maximum-white-tiles-covered-by-a-carpet
2640-maximum-number-of-integers-to-choose-from-a-range-i

Bit Manipulation

0067-add-binary
0078-subsets
0090-subsets-ii
0136-single-number
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0231-power-of-two
0268-missing-number
0287-find-the-duplicate-number
0342-power-of-four
0421-maximum-xor-of-two-numbers-in-an-array
2323-minimum-bit-flips-to-convert-number

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
1396-count-servers-that-communicate

Combinatorics

0062-unique-paths

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions
0200-number-of-islands
0399-evaluate-division
0547-number-of-provinces
0684-redundant-connection
0685-redundant-connection-ii
0695-max-area-of-island
0721-accounts-merge
0801-is-graph-bipartite
1032-satisfiability-of-equality-equations
1058-lexicographically-smallest-equivalent-string
1073-number-of-enclaves
1380-number-of-closed-islands
1396-count-servers-that-communicate
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
2121-find-if-path-exists-in-graph

String

0003-longest-substring-without-repeating-characters
0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0032-longest-valid-parentheses
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0072-edit-distance
0076-minimum-window-substring
0079-word-search
0091-decode-ways
0125-valid-palindrome
0131-palindrome-partitioning
0132-palindrome-partitioning-ii
0208-implement-trie-prefix-tree
0242-valid-anagram
0392-is-subsequence
0399-evaluate-division
0516-longest-palindromic-subsequence
0721-accounts-merge
1032-satisfiability-of-equality-equations
1058-lexicographically-smallest-equivalent-string
1250-longest-common-subsequence
1353-find-resultant-array-after-removing-anagrams
1437-minimum-insertion-steps-to-make-a-string-palindrome
1970-sorting-the-sentence
3329-find-the-length-of-the-longest-common-prefix
3732-calculate-score-after-performing-instructions

Sliding Window

0003-longest-substring-without-repeating-characters
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0219-contains-duplicate-ii
0239-sliding-window-maximum
1966-frequency-of-the-most-frequent-element
2359-maximum-white-tiles-covered-by-a-carpet

Stack

0020-valid-parentheses
0032-longest-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
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
0150-evaluate-reverse-polish-notation
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0234-palindrome-linked-list
0739-daily-temperatures
0937-online-stock-span
1050-construct-binary-search-tree-from-preorder-traversal

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0739-daily-temperatures
0937-online-stock-span
1050-construct-binary-search-tree-from-preorder-traversal

Backtracking

0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0047-permutations-ii
0078-subsets
0079-word-search
0090-subsets-ii
0113-path-sum-ii
0131-palindrome-partitioning

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0239-sliding-window-maximum
0295-find-median-from-data-stream
0347-top-k-frequent-elements
0373-find-k-pairs-with-smallest-sums
0744-network-delay-time
0789-kth-largest-element-in-a-stream
0803-cheapest-flights-within-k-stops
1014-k-closest-points-to-origin
1127-last-stone-weight
1325-path-with-maximum-probability
1753-path-with-minimum-effort

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
1014-k-closest-points-to-origin

Design

0146-lru-cache
0155-min-stack
0208-implement-trie-prefix-tree
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream
0817-design-hashmap
0937-online-stock-span

Data Stream

0295-find-median-from-data-stream
0789-kth-largest-element-in-a-stream
0937-online-stock-span

Bucket Sort

0347-top-k-frequent-elements

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum

Doubly-Linked List

0146-lru-cache

Monotonic Queue

0239-sliding-window-maximum

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
0112-path-sum
0130-surrounded-regions
0200-number-of-islands
0207-course-schedule
0210-course-schedule-ii
0226-invert-binary-tree
0279-perfect-squares
0322-coin-change
0399-evaluate-division
0417-pacific-atlantic-water-flow
0547-number-of-provinces
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0684-redundant-connection
0685-redundant-connection-ii
0695-max-area-of-island
0721-accounts-merge
0733-flood-fill
0744-network-delay-time
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
1036-rotting-oranges
1073-number-of-enclaves
1116-maximum-level-sum-of-a-binary-tree
1380-number-of-closed-islands
1396-count-servers-that-communicate
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
1757-minimum-jumps-to-reach-home
2121-find-if-path-exists-in-graph

Tree

0094-binary-tree-inorder-traversal
0098-validate-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
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0112-path-sum
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
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
0543-diameter-of-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0832-binary-tree-pruning
0975-range-sum-of-bst
1050-construct-binary-search-tree-from-preorder-traversal
1116-maximum-level-sum-of-a-binary-tree
1285-balance-a-binary-search-tree
1427-all-elements-in-two-binary-search-trees

Depth-First Search

0079-word-search
0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0112-path-sum
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0130-surrounded-regions
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0200-number-of-islands
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
0399-evaluate-division
0417-pacific-atlantic-water-flow
0543-diameter-of-binary-tree
0547-number-of-provinces
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0684-redundant-connection
0685-redundant-connection-ii
0695-max-area-of-island
0721-accounts-merge
0733-flood-fill
0744-network-delay-time
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
0832-binary-tree-pruning
0975-range-sum-of-bst
1073-number-of-enclaves
1116-maximum-level-sum-of-a-binary-tree
1285-balance-a-binary-search-tree
1380-number-of-closed-islands
1396-count-servers-that-communicate
1427-all-elements-in-two-binary-search-trees
1442-number-of-operations-to-make-network-connected
1753-path-with-minimum-effort
2121-find-if-path-exists-in-graph

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-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
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0112-path-sum
0113-path-sum-ii
0114-flatten-binary-tree-to-linked-list
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
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
0543-diameter-of-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0832-binary-tree-pruning
0975-range-sum-of-bst
1050-construct-binary-search-tree-from-preorder-traversal
1116-maximum-level-sum-of-a-binary-tree
1285-balance-a-binary-search-tree
1427-all-elements-in-two-binary-search-trees

Binary Search Tree

0098-validate-binary-search-tree
0108-convert-sorted-array-to-binary-search-tree
0230-kth-smallest-element-in-a-bst
0235-lowest-common-ancestor-of-a-binary-search-tree
0653-two-sum-iv-input-is-a-bst
0783-search-in-a-binary-search-tree
0784-insert-into-a-binary-search-tree
0789-kth-largest-element-in-a-stream
0975-range-sum-of-bst
1050-construct-binary-search-tree-from-preorder-traversal
1285-balance-a-binary-search-tree
1427-all-elements-in-two-binary-search-trees

Graph

0207-course-schedule
0210-course-schedule-ii
0399-evaluate-division
0547-number-of-provinces
0684-redundant-connection
0685-redundant-connection-ii
0744-network-delay-time
0801-is-graph-bipartite
0803-cheapest-flights-within-k-stops
0820-find-eventual-safe-states
1032-satisfiability-of-equality-equations
1325-path-with-maximum-probability
1442-number-of-operations-to-make-network-connected
2121-find-if-path-exists-in-graph

Topological Sort

0207-course-schedule
0210-course-schedule-ii
0820-find-eventual-safe-states

Trie

0014-longest-common-prefix
0208-implement-trie-prefix-tree
0421-maximum-xor-of-two-numbers-in-an-array
3329-find-the-length-of-the-longest-common-prefix

Memoization

0070-climbing-stairs
1013-fibonacci-number

String Matching

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

Simulation

0067-add-binary
1378-cells-with-odd-values-in-a-matrix
2048-build-array-from-permutation
2058-concatenation-of-array
2698-find-the-array-concatenation-value
3732-calculate-score-after-performing-instructions

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0560-subarray-sum-equals-k
1603-running-sum-of-1d-array
1966-frequency-of-the-most-frequent-element
2359-maximum-white-tiles-covered-by-a-carpet

Rejection Sampling

0903-implement-rand10-using-rand7

Randomized

0903-implement-rand10-using-rand7

Probability and Statistics

0903-implement-rand10-using-rand7

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0135-candy
0435-non-overlapping-intervals
0452-minimum-number-of-arrows-to-burst-balloons
0611-valid-triangle-number
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0853-most-profit-assigning-work
1047-maximize-sum-of-array-after-k-negations
1285-balance-a-binary-search-tree
1966-frequency-of-the-most-frequent-element
2117-find-original-array-from-doubled-array
2359-maximum-white-tiles-covered-by-a-carpet
2640-maximum-number-of-integers-to-choose-from-a-range-i

Hash Function

0817-design-hashmap

Geometry

1014-k-closest-points-to-origin

Interactive

0278-first-bad-version
0374-guess-number-higher-or-lower
1185-find-in-mountain-array

Shortest Path

0399-evaluate-division
0744-network-delay-time
0803-cheapest-flights-within-k-stops
1325-path-with-maximum-probability

Database

0175-combine-two-tables
0176-second-highest-salary
0177-nth-highest-salary
0178-rank-scores
0181-employees-earning-more-than-their-managers
0182-duplicate-emails
0183-customers-who-never-order
0184-department-highest-salary
0196-delete-duplicate-emails
0570-managers-with-at-least-5-direct-reports
0577-employee-bonus
0584-find-customer-referee
0586-customer-placing-the-largest-number-of-orders
0595-big-countries
0596-classes-with-at-least-5-students
0607-sales-person
0610-triangle-judgement
0619-biggest-single-number
0620-not-boring-movies
0626-exchange-seats
0627-swap-salary
1135-customers-who-bought-all-products
1153-product-sales-analysis-i
1155-product-sales-analysis-iii
1161-project-employees-i
1174-sales-analysis-iii
1179-game-play-analysis-i
1258-article-views-i
1301-reformat-department-table

Enumeration

0204-count-primes

Number Theory

0204-count-primes

Merge Sort

0148-sort-list