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

LeetCode Topics

Two Pointers

0005-longest-palindromic-substring
0011-container-with-most-water
0015-3sum
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
0125-valid-palindrome
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0189-rotate-array
0234-palindrome-linked-list
0283-move-zeroes
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0392-is-subsequence
0443-string-compression
0455-assign-cookies
0567-permutation-in-string
0647-palindromic-substrings
0680-valid-palindrome-ii
0874-backspace-string-compare
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list
2271-rearrange-array-elements-by-sign

String

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
0043-multiply-strings
0049-group-anagrams
0067-add-binary
0076-minimum-window-substring
0125-valid-palindrome
0131-palindrome-partitioning
0139-word-break
0151-reverse-words-in-a-string
0205-isomorphic-strings
0242-valid-anagram
0290-word-pattern
0387-first-unique-character-in-a-string
0392-is-subsequence
0402-remove-k-digits
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0443-string-compression
0451-sort-characters-by-frequency
0567-permutation-in-string
0647-palindromic-substrings
0680-valid-palindrome-ii
0778-reorganize-string
0812-rotate-string
0874-backspace-string-compare
1078-remove-outermost-parentheses
1128-remove-all-adjacent-duplicates-in-string
1460-number-of-substrings-containing-all-three-characters
1737-maximum-nesting-depth-of-the-parentheses
1890-sum-of-beauty-of-all-substrings
2032-largest-odd-number-in-string

Math

0002-add-two-numbers
0012-integer-to-roman
0013-roman-to-integer
0043-multiply-strings
0048-rotate-image
0050-powx-n
0067-add-binary
0189-rotate-array
0268-missing-number
1013-fibonacci-number
1370-count-number-of-nice-subarrays
2032-largest-odd-number-in-string
2050-count-good-numbers

Dynamic Programming

0005-longest-palindromic-substring
0022-generate-parentheses
0042-trapping-rain-water
0053-maximum-subarray
0121-best-time-to-buy-and-sell-stock
0124-binary-tree-maximum-path-sum
0131-palindrome-partitioning
0139-word-break
0152-maximum-product-subarray
0392-is-subsequence
0647-palindromic-substrings
0943-sum-of-subarray-minimums
1013-fibonacci-number

Recursion

0002-add-two-numbers
0021-merge-two-sorted-lists
0050-powx-n
0206-reverse-linked-list
0234-palindrome-linked-list
1013-fibonacci-number
2050-count-good-numbers

Memoization

0139-word-break
1013-fibonacci-number

Array

0001-two-sum
0004-median-of-two-sorted-arrays
0011-container-with-most-water
0015-3sum
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
0051-n-queens
0053-maximum-subarray
0054-spiral-matrix
0056-merge-intervals
0073-set-matrix-zeroes
0075-sort-colors
0078-subsets
0081-search-in-rotated-sorted-array-ii
0084-largest-rectangle-in-histogram
0088-merge-sorted-array
0090-subsets-ii
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0136-single-number
0139-word-break
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0189-rotate-array
0209-minimum-size-subarray-sum
0216-combination-sum-iii
0217-contains-duplicate
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
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0442-find-all-duplicates-in-an-array
0455-assign-cookies
0485-max-consecutive-ones
0496-next-greater-element-i
0503-next-greater-element-ii
0540-single-element-in-a-sorted-array
0560-subarray-sum-equals-k
0621-task-scheduler
0735-asteroid-collision
0792-binary-search
0907-koko-eating-bananas
0940-fruit-into-baskets
0943-sum-of-subarray-minimums
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1036-rotting-oranges
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1370-count-number-of-nice-subarrays
1408-find-the-smallest-divisor-given-a-threshold
1538-maximum-points-you-can-obtain-from-cards
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number
1878-check-if-array-is-sorted-and-rotated
2227-sum-of-subarray-ranges
2271-rearrange-array-elements-by-sign
2552-maximum-sum-of-distinct-subarrays-with-length-k

Hash Table

0001-two-sum
0012-integer-to-roman
0013-roman-to-integer
0017-letter-combinations-of-a-phone-number
0049-group-anagrams
0073-set-matrix-zeroes
0076-minimum-window-substring
0128-longest-consecutive-sequence
0139-word-break
0142-linked-list-cycle-ii
0146-lru-cache
0205-isomorphic-strings
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0290-word-pattern
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0387-first-unique-character-in-a-string
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0442-find-all-duplicates-in-an-array
0451-sort-characters-by-frequency
0496-next-greater-element-i
0560-subarray-sum-equals-k
0567-permutation-in-string
0621-task-scheduler
0778-reorganize-string
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1029-vertical-order-traversal-of-a-binary-tree
1034-subarrays-with-k-different-integers
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1890-sum-of-beauty-of-all-substrings
2552-maximum-sum-of-distinct-subarrays-with-length-k

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
0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0209-minimum-size-subarray-sum
0268-missing-number
0287-find-the-duplicate-number
0349-intersection-of-two-arrays
0540-single-element-in-a-sorted-array
0792-binary-search
0907-koko-eating-bananas
1046-max-consecutive-ones-iii
1056-capacity-to-ship-packages-within-d-days
1408-find-the-smallest-divisor-given-a-threshold
1605-minimum-number-of-days-to-make-m-bouquets
1646-kth-missing-positive-number

Bit Manipulation

0067-add-binary
0078-subsets
0090-subsets-ii
0136-single-number
0268-missing-number
0287-find-the-duplicate-number
2323-minimum-bit-flips-to-convert-number

Sorting

0015-3sum
0049-group-anagrams
0056-merge-intervals
0075-sort-colors
0088-merge-sorted-array
0148-sort-list
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0268-missing-number
0347-top-k-frequent-elements
0349-intersection-of-two-arrays
0451-sort-characters-by-frequency
0455-assign-cookies
0621-task-scheduler
0778-reorganize-string
1029-vertical-order-traversal-of-a-binary-tree

Divide and Conquer

0004-median-of-two-sorted-arrays
0023-merge-k-sorted-lists
0053-maximum-subarray
0148-sort-list
0347-top-k-frequent-elements

Simulation

0043-multiply-strings
0054-spiral-matrix
0067-add-binary
0735-asteroid-collision
0874-backspace-string-compare
2271-rearrange-array-elements-by-sign

Union Find

0128-longest-consecutive-sequence

Matrix

0048-rotate-image
0054-spiral-matrix
0073-set-matrix-zeroes
1036-rotting-oranges

Stack

0020-valid-parentheses
0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0094-binary-tree-inorder-traversal
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0155-min-stack
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
0874-backspace-string-compare
0937-online-stock-span
0943-sum-of-subarray-minimums
1078-remove-outermost-parentheses
1128-remove-all-adjacent-duplicates-in-string
1737-maximum-nesting-depth-of-the-parentheses
2227-sum-of-subarray-ranges

Greedy

0011-container-with-most-water
0402-remove-k-digits
0455-assign-cookies
0621-task-scheduler
0680-valid-palindrome-ii
0778-reorganize-string
2032-largest-odd-number-in-string

Trie

0014-longest-common-prefix
0139-word-break

String Matching

0028-find-the-index-of-the-first-occurrence-in-a-string
0812-rotate-string

Heap (Priority Queue)

0023-merge-k-sorted-lists
0239-sliding-window-maximum
0347-top-k-frequent-elements
0451-sort-characters-by-frequency
0621-task-scheduler
0778-reorganize-string
0789-kth-largest-element-in-a-stream

Bucket Sort

0347-top-k-frequent-elements
0451-sort-characters-by-frequency

Counting

0229-majority-element-ii
0347-top-k-frequent-elements
0387-first-unique-character-in-a-string
0451-sort-characters-by-frequency
0621-task-scheduler
0778-reorganize-string
1034-subarrays-with-k-different-integers
1890-sum-of-beauty-of-all-substrings

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0023-merge-k-sorted-lists
0061-rotate-list
0142-linked-list-cycle-ii
0146-lru-cache
0148-sort-list
0206-reverse-linked-list
0234-palindrome-linked-list
0237-delete-node-in-a-linked-list
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list

Merge Sort

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

Design

0146-lru-cache
0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0789-kth-largest-element-in-a-stream
0937-online-stock-span

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0239-sliding-window-maximum
0387-first-unique-character-in-a-string

Monotonic Stack

0042-trapping-rain-water
0084-largest-rectangle-in-histogram
0402-remove-k-digits
0496-next-greater-element-i
0503-next-greater-element-ii
0937-online-stock-span
0943-sum-of-subarray-minimums
2227-sum-of-subarray-ranges

Sliding Window

0076-minimum-window-substring
0209-minimum-size-subarray-sum
0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0438-find-all-anagrams-in-a-string
0567-permutation-in-string
0940-fruit-into-baskets
0966-binary-subarrays-with-sum
1034-subarrays-with-k-different-integers
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1460-number-of-substrings-containing-all-three-characters
1538-maximum-points-you-can-obtain-from-cards
2552-maximum-sum-of-distinct-subarrays-with-length-k

Monotonic Queue

0239-sliding-window-maximum

Data Stream

0789-kth-largest-element-in-a-stream
0937-online-stock-span

Doubly-Linked List

0146-lru-cache

Prefix Sum

0209-minimum-size-subarray-sum
0238-product-of-array-except-self
0560-subarray-sum-equals-k
0966-binary-subarrays-with-sum
1046-max-consecutive-ones-iii
1370-count-number-of-nice-subarrays
1538-maximum-points-you-can-obtain-from-cards

Quickselect

0347-top-k-frequent-elements

Backtracking

0017-letter-combinations-of-a-phone-number
0022-generate-parentheses
0039-combination-sum
0040-combination-sum-ii
0046-permutations
0051-n-queens
0078-subsets
0090-subsets-ii
0131-palindrome-partitioning
0216-combination-sum-iii

Tree

0094-binary-tree-inorder-traversal
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
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0789-kth-largest-element-in-a-stream
1029-vertical-order-traversal-of-a-binary-tree

Binary Search Tree

0789-kth-largest-element-in-a-stream

Binary Tree

0094-binary-tree-inorder-traversal
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
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
0789-kth-largest-element-in-a-stream
1029-vertical-order-traversal-of-a-binary-tree

Depth-First Search

0094-binary-tree-inorder-traversal
0100-same-tree
0101-symmetric-tree
0104-maximum-depth-of-binary-tree
0110-balanced-binary-tree
0124-binary-tree-maximum-path-sum
0144-binary-tree-preorder-traversal
0145-binary-tree-postorder-traversal
0199-binary-tree-right-side-view
1029-vertical-order-traversal-of-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
0199-binary-tree-right-side-view
1029-vertical-order-traversal-of-a-binary-tree
1036-rotting-oranges