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

LeetCode Topics

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
0037-sudoku-solver
0041-first-missing-positive
0049-group-anagrams
0076-minimum-window-substring
0141-linked-list-cycle
0142-linked-list-cycle-ii
0169-majority-element
0208-implement-trie-prefix-tree
0229-majority-element-ii
0242-valid-anagram
0347-top-k-frequent-elements
0560-subarray-sum-equals-k
0621-task-scheduler
0870-magic-squares-in-grid
1460-number-of-substrings-containing-all-three-characters
1502-construct-k-palindrome-strings
2695-find-score-of-an-array-after-marking-all-elements

Linked List

0002-add-two-numbers
0021-merge-two-sorted-lists
0114-flatten-binary-tree-to-linked-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
0147-insertion-sort-list
0206-reverse-linked-list

Two Pointers

0011-container-with-most-water
0015-3sum
0026-remove-duplicates-from-sorted-array
0027-remove-element
0028-find-the-index-of-the-first-occurrence-in-a-string
0042-trapping-rain-water
0080-remove-duplicates-from-sorted-array-ii
0088-merge-sorted-array
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0151-reverse-words-in-a-string
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0283-move-zeroes
0455-assign-cookies
0658-find-k-closest-elements
0719-find-k-th-smallest-pair-distance

Array

0001-two-sum
0011-container-with-most-water
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
0041-first-missing-positive
0042-trapping-rain-water
0045-jump-game-ii
0049-group-anagrams
0054-spiral-matrix
0055-jump-game
0056-merge-intervals
0057-insert-interval
0080-remove-duplicates-from-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
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
0134-gas-station
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0189-rotate-array
0200-number-of-islands
0209-minimum-size-subarray-sum
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0238-product-of-array-except-self
0274-h-index
0283-move-zeroes
0347-top-k-frequent-elements
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0498-diagonal-traverse
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0621-task-scheduler
0643-maximum-average-subarray-i
0658-find-k-closest-elements
0719-find-k-th-smallest-pair-distance
0792-binary-search
0870-magic-squares-in-grid
0921-spiral-matrix-iii
1240-stone-game-ii
1293-three-consecutive-odds
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1720-crawler-log-folder
1803-average-waiting-time
1917-maximum-average-pass-ratio
2277-count-equal-and-divisible-pairs-in-an-array
2695-find-score-of-an-array-after-marking-all-elements
2846-robot-collisions
2868-continuous-subarrays
3463-alternating-groups-i

Matrix

0036-valid-sudoku
0037-sudoku-solver
0054-spiral-matrix
0200-number-of-islands
0498-diagonal-traverse
0870-magic-squares-in-grid
0921-spiral-matrix-iii

Simulation

0043-multiply-strings
0054-spiral-matrix
0498-diagonal-traverse
0921-spiral-matrix-iii
1803-average-waiting-time
2645-pass-the-pillow
2695-find-score-of-an-array-after-marking-all-elements
2846-robot-collisions

Stack

0042-trapping-rain-water
0071-simplify-path
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0114-flatten-binary-tree-to-linked-list
0155-min-stack
1298-reverse-substrings-between-each-pair-of-parentheses
1720-crawler-log-folder
2846-robot-collisions

Design

0155-min-stack
0208-implement-trie-prefix-tree

String

0003-longest-substring-without-repeating-characters
0006-zigzag-conversion
0014-longest-common-prefix
0028-find-the-index-of-the-first-occurrence-in-a-string
0030-substring-with-concatenation-of-all-words
0038-count-and-say
0043-multiply-strings
0049-group-anagrams
0058-length-of-last-word
0071-simplify-path
0076-minimum-window-substring
0125-valid-palindrome
0151-reverse-words-in-a-string
0208-implement-trie-prefix-tree
0242-valid-anagram
0257-binary-tree-paths
1298-reverse-substrings-between-each-pair-of-parentheses
1460-number-of-substrings-containing-all-three-characters
1502-construct-k-palindrome-strings
1720-crawler-log-folder
2217-step-by-step-directions-from-a-binary-tree-node-to-another

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
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0621-task-scheduler
1502-construct-k-palindrome-strings
1515-find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
1917-maximum-average-pass-ratio

Sorting

0015-3sum
0049-group-anagrams
0056-merge-intervals
0088-merge-sorted-array
0147-insertion-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0229-majority-element-ii
0242-valid-anagram
0274-h-index
0347-top-k-frequent-elements
0452-minimum-number-of-arrows-to-burst-balloons
0455-assign-cookies
0621-task-scheduler
0658-find-k-closest-elements
0719-find-k-th-smallest-pair-distance
1616-minimum-difference-between-largest-and-smallest-value-in-three-moves
2695-find-score-of-an-array-after-marking-all-elements
2846-robot-collisions

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram

Divide and Conquer

0169-majority-element
0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Heap (Priority Queue)

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements
0621-task-scheduler
0658-find-k-closest-elements
1917-maximum-average-pass-ratio
2695-find-score-of-an-array-after-marking-all-elements
2868-continuous-subarrays

Quickselect

0215-kth-largest-element-in-an-array
0347-top-k-frequent-elements

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0621-task-scheduler
1502-construct-k-palindrome-strings

Math

0002-add-two-numbers
0009-palindrome-number
0043-multiply-strings
0189-rotate-array
0650-2-keys-keyboard
0870-magic-squares-in-grid
1240-stone-game-ii
1515-find-the-minimum-number-of-fibonacci-numbers-whose-sum-is-k
2050-count-good-numbers
2645-pass-the-pillow

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0153-find-minimum-in-rotated-sorted-array
0167-two-sum-ii-input-array-is-sorted
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0278-first-bad-version
0540-single-element-in-a-sorted-array
0658-find-k-closest-elements
0719-find-k-th-smallest-pair-distance
0792-binary-search

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0209-minimum-size-subarray-sum
0643-maximum-average-subarray-i
0658-find-k-closest-elements
1460-number-of-substrings-containing-all-three-characters
2868-continuous-subarrays
3463-alternating-groups-i

Bucket Sort

0347-top-k-frequent-elements

Dynamic Programming

0042-trapping-rain-water
0045-jump-game-ii
0055-jump-game
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
0650-2-keys-keyboard
1240-stone-game-ii

Interactive

0278-first-bad-version

Backtracking

0037-sudoku-solver
0257-binary-tree-paths

Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0114-flatten-binary-tree-to-linked-list
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0543-diameter-of-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another

Depth-First Search

0094-binary-tree-inorder-traversal
0104-maximum-depth-of-binary-tree
0114-flatten-binary-tree-to-linked-list
0199-binary-tree-right-side-view
0200-number-of-islands
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0543-diameter-of-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another

Binary Tree

0094-binary-tree-inorder-traversal
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0114-flatten-binary-tree-to-linked-list
0199-binary-tree-right-side-view
0222-count-complete-tree-nodes
0235-lowest-common-ancestor-of-a-binary-search-tree
0236-lowest-common-ancestor-of-a-binary-tree
0257-binary-tree-paths
0543-diameter-of-binary-tree
2217-step-by-step-directions-from-a-binary-tree-node-to-another

Breadth-First Search

0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0199-binary-tree-right-side-view
0200-number-of-islands

Union Find

0200-number-of-islands

Counting Sort

0274-h-index

String Matching

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

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0560-subarray-sum-equals-k
1240-stone-game-ii

Game Theory

1240-stone-game-ii

Trie

0014-longest-common-prefix
0208-implement-trie-prefix-tree

Database

0197-rising-temperature
0584-find-customer-referee
0595-big-countries
0620-not-boring-movies
1153-product-sales-analysis-i
1258-article-views-i
1509-replace-employee-id-with-the-unique-identifier
1724-customer-who-visited-but-did-not-make-any-transactions
1827-invalid-tweets
1908-recyclable-and-low-fat-products
2495-number-of-unique-subjects-taught-by-each-teacher

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0206-reverse-linked-list
2050-count-good-numbers

Bit Manipulation

0222-count-complete-tree-nodes

Binary Search Tree

0235-lowest-common-ancestor-of-a-binary-search-tree

Queue

2868-continuous-subarrays

Ordered Set

2868-continuous-subarrays

Monotonic Queue

2868-continuous-subarrays