leetcode

Collection of LeetCode questions to ace the coding interview! - Created using LeetHub

LeetCode Topics

Array

0001-two-sum
0004-median-of-two-sorted-arrays
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
0039-combination-sum
0042-trapping-rain-water
0045-jump-game-ii
0046-permutations
0047-permutations-ii
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
0068-text-justification
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0079-word-search
0080-remove-duplicates-from-sorted-array-ii
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0128-longest-consecutive-sequence
0130-surrounded-regions
0134-gas-station
0135-candy
0136-single-number
0137-single-number-ii
0139-word-break
0149-max-points-on-a-line
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0189-rotate-array
0198-house-robber
0200-number-of-islands
0209-minimum-size-subarray-sum
0212-word-search-ii
0215-kth-largest-element-in-an-array
0228-summary-ranges
0238-product-of-array-except-self
0274-h-index
0289-game-of-life
0300-longest-increasing-subsequence
0322-coin-change
0380-insert-delete-getrandom-o1
0399-evaluate-division
0452-minimum-number-of-arrows-to-burst-balloons
0502-ipo
0772-construct-quad-tree
0945-snakes-and-ladders
0954-maximum-sum-circular-subarray
1700-minimum-time-to-make-rope-colorful

Two Pointers

0005-longest-palindromic-substring
0019-remove-nth-node-from-end-of-list
0026-remove-duplicates-from-sorted-array
0027-remove-element
0042-trapping-rain-water
0061-rotate-list
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0125-valid-palindrome
0141-linked-list-cycle
0148-sort-list
0151-reverse-words-in-a-string
0189-rotate-array
0202-happy-number
0295-find-median-from-data-stream
0392-is-subsequence

Depth-First Search

0104-maximum-depth-of-binary-tree
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0130-surrounded-regions
0133-clone-graph
0200-number-of-islands
0207-course-schedule
0211-design-add-and-search-words-data-structure
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0399-evaluate-division
0530-minimum-absolute-difference-in-bst

Breadth-First Search

0103-binary-tree-zigzag-level-order-traversal
0104-maximum-depth-of-binary-tree
0112-path-sum
0117-populating-next-right-pointers-in-each-node-ii
0127-word-ladder
0130-surrounded-regions
0133-clone-graph
0200-number-of-islands
0207-course-schedule
0226-invert-binary-tree
0279-perfect-squares
0322-coin-change
0399-evaluate-division
0433-minimum-genetic-mutation
0530-minimum-absolute-difference-in-bst
0945-snakes-and-ladders

Union Find

0128-longest-consecutive-sequence
0130-surrounded-regions
0200-number-of-islands
0399-evaluate-division

Matrix

0036-valid-sudoku
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
0130-surrounded-regions
0200-number-of-islands
0212-word-search-ii
0289-game-of-life
0772-construct-quad-tree
0945-snakes-and-ladders

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
0030-substring-with-concatenation-of-all-words
0036-valid-sudoku
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
0127-word-ladder
0128-longest-consecutive-sequence
0133-clone-graph
0138-copy-list-with-random-pointer
0139-word-break
0141-linked-list-cycle
0146-lru-cache
0149-max-points-on-a-line
0169-majority-element
0202-happy-number
0205-isomorphic-strings
0208-implement-trie-prefix-tree
0242-valid-anagram
0290-word-pattern
0380-insert-delete-getrandom-o1
0433-minimum-genetic-mutation

Graph

0133-clone-graph
0207-course-schedule
0399-evaluate-division
2379-maximum-total-importance-of-roads

String

0003-longest-substring-without-repeating-characters
0005-longest-palindromic-substring
0006-zigzag-conversion
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0030-substring-with-concatenation-of-all-words
0049-group-anagrams
0058-length-of-last-word
0067-add-binary
0068-text-justification
0076-minimum-window-substring
0079-word-search
0097-interleaving-string
0125-valid-palindrome
0127-word-ladder
0139-word-break
0151-reverse-words-in-a-string
0205-isomorphic-strings
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii
0227-basic-calculator-ii
0242-valid-anagram
0290-word-pattern
0392-is-subsequence
0399-evaluate-division
0433-minimum-genetic-mutation
1700-minimum-time-to-make-rope-colorful

Shortest Path

0399-evaluate-division

Topological Sort

0207-course-schedule

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
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0209-minimum-size-subarray-sum
0222-count-complete-tree-nodes
0300-longest-increasing-subsequence

Tree

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
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0173-binary-search-tree-iterator
0222-count-complete-tree-nodes
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0450-delete-node-in-a-bst
0530-minimum-absolute-difference-in-bst
0772-construct-quad-tree

Binary Tree

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
0112-path-sum
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0124-binary-tree-maximum-path-sum
0129-sum-root-to-leaf-numbers
0173-binary-search-tree-iterator
0222-count-complete-tree-nodes
0226-invert-binary-tree
0236-lowest-common-ancestor-of-a-binary-tree
0450-delete-node-in-a-bst
0530-minimum-absolute-difference-in-bst

Trie

0014-longest-common-prefix
0139-word-break
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0212-word-search-ii

Math

0002-add-two-numbers
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0050-powx-n
0066-plus-one
0067-add-binary
0069-sqrtx
0070-climbing-stairs
0149-max-points-on-a-line
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0227-basic-calculator-ii
0279-perfect-squares
0380-insert-delete-getrandom-o1

Bit Manipulation

0067-add-binary
0136-single-number
0137-single-number-ii
0190-reverse-bits
0191-number-of-1-bits
0222-count-complete-tree-nodes

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0105-construct-binary-tree-from-preorder-and-inorder-traversal
0106-construct-binary-tree-from-inorder-and-postorder-traversal
0148-sort-list
0169-majority-element
0190-reverse-bits
0191-number-of-1-bits
0215-kth-largest-element-in-an-array
0772-construct-quad-tree
0954-maximum-sum-circular-subarray

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0025-reverse-nodes-in-k-group
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0092-reverse-linked-list-ii
0114-flatten-binary-tree-to-linked-list
0117-populating-next-right-pointers-in-each-node-ii
0138-copy-list-with-random-pointer
0141-linked-list-cycle
0146-lru-cache
0148-sort-list

Sorting

0049-group-anagrams
0056-merge-intervals
0148-sort-list
0169-majority-element
0215-kth-largest-element-in-an-array
0242-valid-anagram
0274-h-index
0295-find-median-from-data-stream
0452-minimum-number-of-arrows-to-burst-balloons
0502-ipo
2379-maximum-total-importance-of-roads

Counting Sort

0169-majority-element
0274-h-index

Stack

0042-trapping-rain-water
0114-flatten-binary-tree-to-linked-list
0173-binary-search-tree-iterator
0227-basic-calculator-ii

Design

0146-lru-cache
0173-binary-search-tree-iterator
0208-implement-trie-prefix-tree
0211-design-add-and-search-words-data-structure
0295-find-median-from-data-stream
0380-insert-delete-getrandom-o1

Binary Search Tree

0173-binary-search-tree-iterator
0450-delete-node-in-a-bst
0530-minimum-absolute-difference-in-bst

Iterator

0173-binary-search-tree-iterator

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0045-jump-game-ii
0053-maximum-subarray
0055-jump-game
0063-unique-paths-ii
0064-minimum-path-sum
0070-climbing-stairs
0097-interleaving-string
0120-triangle
0121-best-time-to-buy-and-sell-stock
0122-best-time-to-buy-and-sell-stock-ii
0124-binary-tree-maximum-path-sum
0139-word-break
0198-house-robber
0279-perfect-squares
0300-longest-increasing-subsequence
0322-coin-change
0392-is-subsequence
0954-maximum-sum-circular-subarray
1700-minimum-time-to-make-rope-colorful

Greedy

0045-jump-game-ii
0055-jump-game
0122-best-time-to-buy-and-sell-stock-ii
0134-gas-station
0135-candy
0452-minimum-number-of-arrows-to-burst-balloons
0502-ipo
1700-minimum-time-to-make-rope-colorful
2379-maximum-total-importance-of-roads

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0025-reverse-nodes-in-k-group
0050-powx-n

Heap (Priority Queue)

0023-merge-k-sorted-lists
0215-kth-largest-element-in-an-array
0295-find-median-from-data-stream
0502-ipo
2379-maximum-total-importance-of-roads

Quickselect

0215-kth-largest-element-in-an-array

Randomized

0380-insert-delete-getrandom-o1

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self

Monotonic Stack

0042-trapping-rain-water

Doubly-Linked List

0146-lru-cache

Simulation

0054-spiral-matrix
0067-add-binary
0068-text-justification
0289-game-of-life

Memoization

0070-climbing-stairs
0139-word-break

Sliding Window

0003-longest-substring-without-repeating-characters
0030-substring-with-concatenation-of-all-words
0076-minimum-window-substring
0209-minimum-size-subarray-sum

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0046-permutations
0047-permutations-ii
0052-n-queens-ii
0077-combinations
0079-word-search
0212-word-search-ii

Merge Sort

0023-merge-k-sorted-lists
0148-sort-list

Queue

0954-maximum-sum-circular-subarray

Monotonic Queue

0954-maximum-sum-circular-subarray

Data Stream

0295-find-median-from-data-stream

Geometry

0149-max-points-on-a-line