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

LeetCode Topics

Math

0007-reverse-integer
0009-palindrome-number
0012-integer-to-roman
0013-roman-to-integer
0048-rotate-image
0062-unique-paths
0066-plus-one
0067-add-binary
0070-climbing-stairs
0150-evaluate-reverse-polish-notation
0172-factorial-trailing-zeroes
0189-rotate-array
0202-happy-number
0380-insert-delete-getrandom-o1
0415-add-strings
1031-add-to-array-form-of-integer
1411-convert-binary-number-in-a-linked-list-to-integer
3606-minimum-element-after-replacement-with-digit-sum

Hash Table

0001-two-sum
0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0073-set-matrix-zeroes
0128-longest-consecutive-sequence
0141-linked-list-cycle
0142-linked-list-cycle-ii
0160-intersection-of-two-linked-lists
0169-majority-element
0202-happy-number
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0347-top-k-frequent-elements
0380-insert-delete-getrandom-o1
0599-minimum-index-sum-of-two-lists
0837-most-common-word
2190-count-common-words-with-one-occurrence
2204-find-subsequence-of-length-k-with-the-largest-sum
2308-divide-array-into-equal-pairs
2634-minimum-common-value
3428-find-the-xor-of-numbers-which-appear-twice
3788-maximum-unique-subarray-sum-after-deletion

String

0003-longest-substring-without-repeating-characters
0012-integer-to-roman
0013-roman-to-integer
0014-longest-common-prefix
0020-valid-parentheses
0028-find-the-index-of-the-first-occurrence-in-a-string
0058-length-of-last-word
0067-add-binary
0071-simplify-path
0125-valid-palindrome
0151-reverse-words-in-a-string
0165-compare-version-numbers
0179-largest-number
0242-valid-anagram
0344-reverse-string
0392-is-subsequence
0415-add-strings
0599-minimum-index-sum-of-two-lists
0837-most-common-word
2190-count-common-words-with-one-occurrence
3396-valid-word

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
0042-trapping-rain-water
0061-rotate-list
0075-sort-colors
0080-remove-duplicates-from-sorted-array-ii
0082-remove-duplicates-from-sorted-list-ii
0086-partition-list
0125-valid-palindrome
0141-linked-list-cycle
0142-linked-list-cycle-ii
0148-sort-list
0151-reverse-words-in-a-string
0160-intersection-of-two-linked-lists
0165-compare-version-numbers
0167-two-sum-ii-input-array-is-sorted
0189-rotate-array
0202-happy-number
0234-palindrome-linked-list
0287-find-the-duplicate-number
0344-reverse-string
0392-is-subsequence
0455-assign-cookies
0528-swapping-nodes-in-a-linked-list
0908-middle-of-the-linked-list
2216-delete-the-middle-node-of-a-linked-list
2634-minimum-common-value

String Matching

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

Stack

0020-valid-parentheses
0042-trapping-rain-water
0071-simplify-path
0094-binary-tree-inorder-traversal
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
0776-n-ary-tree-postorder-traversal
0937-online-stock-span

Array

0001-two-sum
0011-container-with-most-water
0014-longest-common-prefix
0015-3sum
0018-4sum
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
0039-combination-sum
0042-trapping-rain-water
0046-permutations
0047-permutations-ii
0048-rotate-image
0051-n-queens
0053-maximum-subarray
0055-jump-game
0066-plus-one
0073-set-matrix-zeroes
0074-search-a-2d-matrix
0075-sort-colors
0078-subsets
0080-remove-duplicates-from-sorted-array-ii
0090-subsets-ii
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0128-longest-consecutive-sequence
0135-candy
0137-single-number-ii
0150-evaluate-reverse-polish-notation
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0164-maximum-gap
0167-two-sum-ii-input-array-is-sorted
0169-majority-element
0179-largest-number
0189-rotate-array
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0238-product-of-array-except-self
0260-single-number-iii
0287-find-the-duplicate-number
0347-top-k-frequent-elements
0380-insert-delete-getrandom-o1
0455-assign-cookies
0485-max-consecutive-ones
0502-ipo
0506-relative-ranks
0540-single-element-in-a-sorted-array
0599-minimum-index-sum-of-two-lists
0605-can-place-flowers
0837-most-common-word
0882-peak-index-in-a-mountain-array
0932-monotonic-array
1031-add-to-array-form-of-integer
2190-count-common-words-with-one-occurrence
2204-find-subsequence-of-length-k-with-the-largest-sum
2308-divide-array-into-equal-pairs
2316-count-hills-and-valleys-in-an-array
2355-maximum-consecutive-floors-without-special-floors
2634-minimum-common-value
3221-find-the-peaks
3428-find-the-xor-of-numbers-which-appear-twice
3606-minimum-element-after-replacement-with-digit-sum
3788-maximum-unique-subarray-sum-after-deletion

Counting

0169-majority-element
0229-majority-element-ii
0347-top-k-frequent-elements
0837-most-common-word
2190-count-common-words-with-one-occurrence
2308-divide-array-into-equal-pairs

Sorting

0015-3sum
0018-4sum
0047-permutations-ii
0075-sort-colors
0148-sort-list
0164-maximum-gap
0169-majority-element
0179-largest-number
0215-kth-largest-element-in-an-array
0217-contains-duplicate
0229-majority-element-ii
0242-valid-anagram
0347-top-k-frequent-elements
0455-assign-cookies
0502-ipo
0506-relative-ranks
2204-find-subsequence-of-length-k-with-the-largest-sum
2355-maximum-consecutive-floors-without-special-floors

Greedy

0011-container-with-most-water
0055-jump-game
0135-candy
0179-largest-number
0455-assign-cookies
0502-ipo
0605-can-place-flowers
3788-maximum-unique-subarray-sum-after-deletion

Bit Manipulation

0067-add-binary
0078-subsets
0090-subsets-ii
0137-single-number-ii
0260-single-number-iii
0287-find-the-duplicate-number
2308-divide-array-into-equal-pairs
3428-find-the-xor-of-numbers-which-appear-twice

Binary Search

0033-search-in-rotated-sorted-array
0034-find-first-and-last-position-of-element-in-sorted-array
0035-search-insert-position
0074-search-a-2d-matrix
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0167-two-sum-ii-input-array-is-sorted
0287-find-the-duplicate-number
0540-single-element-in-a-sorted-array
0882-peak-index-in-a-mountain-array
2634-minimum-common-value

Simulation

0067-add-binary
0415-add-strings

Bucket Sort

0164-maximum-gap
0347-top-k-frequent-elements

Radix Sort

0164-maximum-gap

Enumeration

3221-find-the-peaks

Matrix

0048-rotate-image
0073-set-matrix-zeroes
0074-search-a-2d-matrix

Dynamic Programming

0042-trapping-rain-water
0053-maximum-subarray
0055-jump-game
0062-unique-paths
0070-climbing-stairs
0118-pascals-triangle
0121-best-time-to-buy-and-sell-stock
0392-is-subsequence

Divide and Conquer

0053-maximum-subarray
0148-sort-list
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
0502-ipo
0506-relative-ranks
2204-find-subsequence-of-length-k-with-the-largest-sum

Union Find

0128-longest-consecutive-sequence

Linked List

0019-remove-nth-node-from-end-of-list
0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0061-rotate-list
0082-remove-duplicates-from-sorted-list-ii
0083-remove-duplicates-from-sorted-list
0086-partition-list
0141-linked-list-cycle
0142-linked-list-cycle-ii
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
0908-middle-of-the-linked-list
1411-convert-binary-number-in-a-linked-list-to-integer
2216-delete-the-middle-node-of-a-linked-list

Recursion

0021-merge-two-sorted-lists
0024-swap-nodes-in-pairs
0203-remove-linked-list-elements
0206-reverse-linked-list
0234-palindrome-linked-list

Merge Sort

0148-sort-list

Memoization

0070-climbing-stairs

Monotonic Stack

0042-trapping-rain-water
0937-online-stock-span

Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
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
0501-find-mode-in-binary-search-tree
0513-find-bottom-left-tree-value
0776-n-ary-tree-postorder-traversal

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
0111-minimum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
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
0501-find-mode-in-binary-search-tree
0513-find-bottom-left-tree-value
0776-n-ary-tree-postorder-traversal

Binary Tree

0094-binary-tree-inorder-traversal
0098-validate-binary-search-tree
0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0113-path-sum-ii
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
0501-find-mode-in-binary-search-tree
0513-find-bottom-left-tree-value

Binary Search Tree

0098-validate-binary-search-tree
0501-find-mode-in-binary-search-tree

Backtracking

0039-combination-sum
0046-permutations
0047-permutations-ii
0051-n-queens
0078-subsets
0090-subsets-ii
0113-path-sum-ii

Quickselect

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

Design

0155-min-stack
0225-implement-stack-using-queues
0232-implement-queue-using-stacks
0380-insert-delete-getrandom-o1
0937-online-stock-span

Queue

0225-implement-stack-using-queues
0232-implement-queue-using-stacks

Breadth-First Search

0100-same-tree
0101-symmetric-tree
0102-binary-tree-level-order-traversal
0104-maximum-depth-of-binary-tree
0111-minimum-depth-of-binary-tree
0112-path-sum
0199-binary-tree-right-side-view
0226-invert-binary-tree
0513-find-bottom-left-tree-value

Randomized

0380-insert-delete-getrandom-o1

Prefix Sum

0238-product-of-array-except-self

Trie

0014-longest-common-prefix

Combinatorics

0062-unique-paths

Sliding Window

0003-longest-substring-without-repeating-characters

Data Stream

0937-online-stock-span