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

LeetCode Topics

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
0107-binary-tree-level-order-traversal-ii
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
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
0257-binary-tree-paths
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0687-longest-univalue-path
0783-search-in-a-binary-search-tree
1029-vertical-order-traversal-of-a-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal
1475-maximum-sum-bst-in-binary-tree
1544-count-good-nodes-in-binary-tree
2646-kth-largest-sum-in-a-binary-tree

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
0107-binary-tree-level-order-traversal-ii
0116-populating-next-right-pointers-in-each-node
0199-binary-tree-right-side-view
0226-invert-binary-tree
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges
1544-count-good-nodes-in-binary-tree
2646-kth-largest-sum-in-a-binary-tree

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
0107-binary-tree-level-order-traversal-ii
0108-convert-sorted-array-to-binary-search-tree
0110-balanced-binary-tree
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
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
0257-binary-tree-paths
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0687-longest-univalue-path
0783-search-in-a-binary-search-tree
1029-vertical-order-traversal-of-a-binary-tree
1050-construct-binary-search-tree-from-preorder-traversal
1475-maximum-sum-bst-in-binary-tree
1544-count-good-nodes-in-binary-tree
2646-kth-largest-sum-in-a-binary-tree

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0018-4sum
0026-remove-duplicates-from-sorted-array
0031-next-permutation
0035-search-insert-position
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
0048-rotate-image
0049-group-anagrams
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
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
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0135-candy
0150-evaluate-reverse-polish-notation
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0209-minimum-size-subarray-sum
0216-combination-sum-iii
0229-majority-element-ii
0239-sliding-window-maximum
0287-find-the-duplicate-number
0455-assign-cookies
0485-max-consecutive-ones
0496-next-greater-element-i
0498-diagonal-traverse
0503-next-greater-element-ii
0611-valid-triangle-number
0645-set-mismatch
0739-daily-temperatures
0883-car-fleet
0890-lemonade-change
1036-rotting-oranges
1046-max-consecutive-ones-iii
1050-construct-binary-search-tree-from-preorder-traversal
1319-unique-number-of-occurrences
1435-xor-queries-of-a-subarray
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit
1657-find-the-winner-of-an-array-game
1829-maximum-units-on-a-truck
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2366-maximum-bags-with-full-capacity-of-rocks
2486-most-frequent-even-element
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array
3227-find-missing-and-repeated-values

Matrix

0037-sudoku-solver
0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0498-diagonal-traverse
1036-rotting-oranges
3227-find-missing-and-repeated-values

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0037-sudoku-solver
0049-group-anagrams
0073-set-matrix-zeroes
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
0146-lru-cache
0160-intersection-of-two-linked-lists
0169-majority-element
0229-majority-element-ii
0242-valid-anagram
0387-first-unique-character-in-a-string
0496-next-greater-element-i
0645-set-mismatch
0653-two-sum-iv-input-is-a-bst
1029-vertical-order-traversal-of-a-binary-tree
1264-maximum-number-of-words-you-can-type
1319-unique-number-of-occurrences
2486-most-frequent-even-element
3227-find-missing-and-repeated-values
3872-find-most-frequent-vowel-and-consonant

Divide and Conquer

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
0169-majority-element

Sorting

0015-3sum
0018-4sum
0047-permutations-ii
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0169-majority-element
0229-majority-element-ii
0242-valid-anagram
0455-assign-cookies
0611-valid-triangle-number
0645-set-mismatch
0883-car-fleet
1029-vertical-order-traversal-of-a-binary-tree
1829-maximum-units-on-a-truck
2366-maximum-bags-with-full-capacity-of-rocks
2497-maximum-matching-of-players-with-trainers
2646-kth-largest-sum-in-a-binary-tree

Counting

0169-majority-element
0229-majority-element-ii
0387-first-unique-character-in-a-string
2486-most-frequent-even-element
3872-find-most-frequent-vowel-and-consonant

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0008-string-to-integer-atoi
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0020-valid-parentheses
0022-generate-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0038-count-and-say
0049-group-anagrams
0131-palindrome-partitioning
0151-reverse-words-in-a-string
0165-compare-version-numbers
0242-valid-anagram
0257-binary-tree-paths
0297-serialize-and-deserialize-binary-tree
0344-reverse-string
0387-first-unique-character-in-a-string
0412-fizz-buzz
0557-reverse-words-in-a-string-iii
0686-repeated-string-match
1264-maximum-number-of-words-you-can-type
1371-minimum-remove-to-make-valid-parentheses
2346-largest-3-same-digit-number-in-string
3462-vowels-game-in-a-string
3872-find-most-frequent-vowel-and-consonant

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-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
0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
0883-car-fleet
0937-online-stock-span
1050-construct-binary-search-tree-from-preorder-traversal
1371-minimum-remove-to-make-valid-parentheses
2307-replace-non-coprime-numbers-in-array

Sliding Window

0003-longest-substring-without-repeating-characters
0209-minimum-size-subarray-sum
0239-sliding-window-maximum
1046-max-consecutive-ones-iii
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
0018-4sum
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
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
0141-linked-list-cycle
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0165-compare-version-numbers
0167-two-sum-ii-input-array-is-sorted
0234-palindrome-linked-list
0287-find-the-duplicate-number
0344-reverse-string
0455-assign-cookies
0528-swapping-nodes-in-a-linked-list
0557-reverse-words-in-a-string-iii
0611-valid-triangle-number
0653-two-sum-iv-input-is-a-bst
0908-middle-of-the-linked-list
2481-strictly-palindromic-number
2497-maximum-matching-of-players-with-trainers
2551-apply-operations-to-an-array

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0118-pascals-triangle
0119-pascals-triangle-ii
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
1475-maximum-sum-bst-in-binary-tree

Math

0002-add-two-numbers
0007-reverse-integer
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0060-permutation-sequence
0062-unique-paths
0150-evaluate-reverse-polish-notation
0326-power-of-three
0342-power-of-four
0412-fizz-buzz
0755-reach-a-number
1440-convert-integer-to-the-sum-of-two-no-zero-integers
1448-maximum-69-number
2307-replace-non-coprime-numbers-in-array
2324-find-triangular-sum-of-an-array
2481-strictly-palindromic-number
3227-find-missing-and-repeated-values
3279-alice-and-bob-playing-flower-game
3462-vowels-game-in-a-string
3830-find-closest-person

Binary Search

0035-search-insert-position
0074-search-a-2d-matrix
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0287-find-the-duplicate-number
0611-valid-triangle-number
0755-reach-a-number
1046-max-consecutive-ones-iii

Bit Manipulation

0078-subsets
0090-subsets-ii
0287-find-the-duplicate-number
0342-power-of-four
0645-set-mismatch
1435-xor-queries-of-a-subarray

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0050-powx-n
0060-permutation-sequence
0206-reverse-linked-list
0234-palindrome-linked-list
0326-power-of-three
0342-power-of-four

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0061-rotate-list
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0160-intersection-of-two-linked-lists
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0528-swapping-nodes-in-a-linked-list
0908-middle-of-the-linked-list

Union Find

0128-longest-consecutive-sequence

Combinatorics

0062-unique-paths
2324-find-triangular-sum-of-an-array

Design

0146-lru-cache
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0297-serialize-and-deserialize-binary-tree
0937-online-stock-span
0969-number-of-recent-calls

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
0387-first-unique-character-in-a-string
0969-number-of-recent-calls
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0496-next-greater-element-i
0503-next-greater-element-ii
0739-daily-temperatures
0883-car-fleet
0937-online-stock-span
1050-construct-binary-search-tree-from-preorder-traversal

Trie

0014-longest-common-prefix

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0572-subtree-of-another-tree
0686-repeated-string-match

Doubly-Linked List

0146-lru-cache

Heap (Priority Queue)

0239-sliding-window-maximum
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Monotonic Queue

0239-sliding-window-maximum
1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Greedy

0011-container-with-most-water
0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0455-assign-cookies
0611-valid-triangle-number
0890-lemonade-change
1448-maximum-69-number
1829-maximum-units-on-a-truck
2366-maximum-bags-with-full-capacity-of-rocks
2497-maximum-matching-of-players-with-trainers

Prefix Sum

0209-minimum-size-subarray-sum
1046-max-consecutive-ones-iii
1435-xor-queries-of-a-subarray

Simulation

0054-spiral-matrix
0412-fizz-buzz
0498-diagonal-traverse
1657-find-the-winner-of-an-array-game
2324-find-triangular-sum-of-an-array
2551-apply-operations-to-an-array

Data Stream

0937-online-stock-span
0969-number-of-recent-calls

Database

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

Ordered Set

1549-longest-continuous-subarray-with-absolute-diff-less-than-or-equal-to-limit

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0037-sudoku-solver
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0047-permutations-ii
0051-n-queens
0052-n-queens-ii
0077-combinations
0078-subsets
0090-subsets-ii
0131-palindrome-partitioning
0216-combination-sum-iii
0257-binary-tree-paths

Depth-First 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
0114-flatten-binary-tree-to-linked-list
0116-populating-next-right-pointers-in-each-node
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
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
0257-binary-tree-paths
0297-serialize-and-deserialize-binary-tree
0513-find-bottom-left-tree-value
0543-diameter-of-binary-tree
0572-subtree-of-another-tree
0637-average-of-levels-in-binary-tree
0653-two-sum-iv-input-is-a-bst
0662-maximum-width-of-binary-tree
0687-longest-univalue-path
1029-vertical-order-traversal-of-a-binary-tree
1475-maximum-sum-bst-in-binary-tree
1544-count-good-nodes-in-binary-tree

Brainteaser

2481-strictly-palindromic-number
3462-vowels-game-in-a-string

Hash Function

0572-subtree-of-another-tree

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
1050-construct-binary-search-tree-from-preorder-traversal
1475-maximum-sum-bst-in-binary-tree

Game Theory

3462-vowels-game-in-a-string

Number Theory

2307-replace-non-coprime-numbers-in-array