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

LeetCode Topics

String

0005-longest-palindromic-substring
0028-find-the-index-of-the-first-occurrence-in-a-string
0038-count-and-say
0079-word-search
0115-distinct-subsequences
0139-word-break
0151-reverse-words-in-a-string
0402-remove-k-digits
0424-longest-repeating-character-replacement
0678-valid-parenthesis-string
0921-minimum-add-to-make-parentheses-valid
3211-generate-binary-strings-without-adjacent-zeros
3499-maximize-active-section-with-trade-i

Dynamic Programming

0005-longest-palindromic-substring
0063-unique-paths-ii
0085-maximal-rectangle
0115-distinct-subsequences
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0124-binary-tree-maximum-path-sum
0139-word-break
0152-maximum-product-subarray
0188-best-time-to-buy-and-sell-stock-iv
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0673-number-of-longest-increasing-subsequence
0678-valid-parenthesis-string
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
1277-count-square-submatrices-with-all-ones
1334-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
1524-number-of-sub-arrays-with-odd-sum

Array

0001-two-sum
0018-4sum
0031-next-permutation
0040-combination-sum-ii
0051-n-queens
0056-merge-intervals
0057-insert-interval
0063-unique-paths-ii
0079-word-search
0081-search-in-rotated-sorted-array-ii
0085-maximal-rectangle
0090-subsets-ii
0122-best-time-to-buy-and-sell-stock-ii
0123-best-time-to-buy-and-sell-stock-iii
0135-candy
0139-word-break
0152-maximum-product-subarray
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0169-majority-element
0188-best-time-to-buy-and-sell-stock-iv
0216-combination-sum-iii
0229-majority-element-ii
0239-sliding-window-maximum
0240-search-a-2d-matrix-ii
0283-move-zeroes
0300-longest-increasing-subsequence
0309-best-time-to-buy-and-sell-stock-with-cooldown
0380-insert-delete-getrandom-o1
0493-reverse-pairs
0560-subarray-sum-equals-k
0621-task-scheduler
0673-number-of-longest-increasing-subsequence
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0778-swim-in-rising-water
0992-subarrays-with-k-different-integers
1277-count-square-submatrices-with-all-ones
1524-number-of-sub-arrays-with-odd-sum
1752-check-if-array-is-sorted-and-rotated
1814-count-nice-pairs-in-an-array
1901-find-a-peak-element-ii
2149-rearrange-array-elements-by-sign
3532-path-existence-queries-in-a-graph-i

Binary Search

0081-search-in-rotated-sorted-array-ii
0153-find-minimum-in-rotated-sorted-array
0162-find-peak-element
0222-count-complete-tree-nodes
0240-search-a-2d-matrix-ii
0300-longest-increasing-subsequence
0493-reverse-pairs
0778-swim-in-rising-water
1901-find-a-peak-element-ii
3532-path-existence-queries-in-a-graph-i

Divide and Conquer

0023-merge-k-sorted-lists
0169-majority-element
0240-search-a-2d-matrix-ii
0493-reverse-pairs

Binary Indexed Tree

0493-reverse-pairs
0673-number-of-longest-increasing-subsequence

Segment Tree

0493-reverse-pairs
0673-number-of-longest-increasing-subsequence

Merge Sort

0023-merge-k-sorted-lists
0493-reverse-pairs

Ordered Set

0493-reverse-pairs

Hash Table

0001-two-sum
0139-word-break
0169-majority-element
0229-majority-element-ii
0355-design-twitter
0380-insert-delete-getrandom-o1
0424-longest-repeating-character-replacement
0460-lfu-cache
0560-subarray-sum-equals-k
0621-task-scheduler
0987-vertical-order-traversal-of-a-binary-tree
0992-subarrays-with-k-different-integers
1814-count-nice-pairs-in-an-array
3532-path-existence-queries-in-a-graph-i

Linked List

0002-add-two-numbers
0019-remove-nth-node-from-end-of-list
0023-merge-k-sorted-lists
0061-rotate-list
0328-odd-even-linked-list
0355-design-twitter
0460-lfu-cache

Design

0355-design-twitter
0380-insert-delete-getrandom-o1
0460-lfu-cache

Heap (Priority Queue)

0023-merge-k-sorted-lists
0239-sliding-window-maximum
0355-design-twitter
0621-task-scheduler
0778-swim-in-rising-water

Math

0002-add-two-numbers
0380-insert-delete-getrandom-o1
1524-number-of-sub-arrays-with-odd-sum
1814-count-nice-pairs-in-an-array

Randomized

0380-insert-delete-getrandom-o1

Matrix

0063-unique-paths-ii
0079-word-search
0085-maximal-rectangle
0240-search-a-2d-matrix-ii
0778-swim-in-rising-water
1277-count-square-submatrices-with-all-ones
1901-find-a-peak-element-ii

Depth-First Search

0079-word-search
0098-validate-binary-search-tree
0124-binary-tree-maximum-path-sum
0210-course-schedule-ii
0230-kth-smallest-element-in-a-bst
0543-diameter-of-binary-tree
0778-swim-in-rising-water
0785-is-graph-bipartite
0987-vertical-order-traversal-of-a-binary-tree

Breadth-First Search

0210-course-schedule-ii
0778-swim-in-rising-water
0785-is-graph-bipartite
0987-vertical-order-traversal-of-a-binary-tree

Union-Find

0778-swim-in-rising-water
0785-is-graph-bipartite
3532-path-existence-queries-in-a-graph-i

Two Pointers

0005-longest-palindromic-substring
0018-4sum
0019-remove-nth-node-from-end-of-list
0028-find-the-index-of-the-first-occurrence-in-a-string
0031-next-permutation
0061-rotate-list
0151-reverse-words-in-a-string
0283-move-zeroes
2149-rearrange-array-elements-by-sign

Sorting

0018-4sum
0056-merge-intervals
0169-majority-element
0229-majority-element-ii
0621-task-scheduler
0987-vertical-order-traversal-of-a-binary-tree

Counting

0169-majority-element
0229-majority-element-ii
0621-task-scheduler
0992-subarrays-with-k-different-integers
1814-count-nice-pairs-in-an-array

Simulation

2149-rearrange-array-elements-by-sign

Prefix Sum

0560-subarray-sum-equals-k
1524-number-of-sub-arrays-with-odd-sum

Tree

0098-validate-binary-search-tree
0124-binary-tree-maximum-path-sum
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0543-diameter-of-binary-tree
0701-insert-into-a-binary-search-tree
0987-vertical-order-traversal-of-a-binary-tree

Binary Tree

0098-validate-binary-search-tree
0124-binary-tree-maximum-path-sum
0222-count-complete-tree-nodes
0230-kth-smallest-element-in-a-bst
0543-diameter-of-binary-tree
0701-insert-into-a-binary-search-tree
0987-vertical-order-traversal-of-a-binary-tree

Binary Search Tree

0098-validate-binary-search-tree
0230-kth-smallest-element-in-a-bst
0701-insert-into-a-binary-search-tree

Doubly-Linked List

0460-lfu-cache

Recursion

0002-add-two-numbers

Graph Theory

0210-course-schedule-ii
0785-is-graph-bipartite
1334-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance
3532-path-existence-queries-in-a-graph-i

Shortest Path

1334-find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance

Bit Manipulation

0090-subsets-ii
0222-count-complete-tree-nodes
3211-generate-binary-strings-without-adjacent-zeros

Backtracking

0040-combination-sum-ii
0051-n-queens
0079-word-search
0090-subsets-ii
0216-combination-sum-iii
3211-generate-binary-strings-without-adjacent-zeros

Stack

0085-maximal-rectangle
0402-remove-k-digits
0678-valid-parenthesis-string
0921-minimum-add-to-make-parentheses-valid

Greedy

0122-best-time-to-buy-and-sell-stock-ii
0135-candy
0402-remove-k-digits
0621-task-scheduler
0678-valid-parenthesis-string
0714-best-time-to-buy-and-sell-stock-with-transaction-fee
0921-minimum-add-to-make-parentheses-valid

String Matching

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

Enumeration

3499-maximize-active-section-with-trade-i

Database

0570-managers-with-at-least-5-direct-reports
0619-biggest-single-number
1045-customers-who-bought-all-products
1070-product-sales-analysis-iii
1075-project-employees-i
1280-students-and-examinations
1661-average-time-of-process-per-machine
1683-invalid-tweets
1731-the-number-of-employees-which-report-to-each-employee
1789-primary-department-for-each-employee
1978-employees-whose-manager-left-the-company

Queue

0239-sliding-window-maximum

Sliding Window

0239-sliding-window-maximum
0424-longest-repeating-character-replacement
0992-subarrays-with-k-different-integers

Monotonic Queue

0239-sliding-window-maximum

Monotonic Stack

0085-maximal-rectangle
0402-remove-k-digits

Trie

0139-word-break

Memoization

0139-word-break

Bracket Sequences

0678-valid-parenthesis-string

Topological Sort

0210-course-schedule-ii