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

LeetCode Topics

Tree

Problem Name	Difficulty
0099-recover-binary-search-tree	Medium
0226-invert-binary-tree	Easy
1373-maximum-sum-bst-in-binary-tree	Hard

Depth-First Search

Problem Name	Difficulty
0099-recover-binary-search-tree	Medium
0226-invert-binary-tree	Easy
1373-maximum-sum-bst-in-binary-tree	Hard

Binary Search Tree

Problem Name	Difficulty
0033-search-in-rotated-sorted-array	Medium
0035-search-insert-position	Easy
0074-search-a-2d-matrix	Medium
0099-recover-binary-search-tree	Medium
0153-find-minimum-in-rotated-sorted-array	Medium
0167-two-sum-ii-input-array-is-sorted	Medium
0704-binary-search	Easy
0875-koko-eating-bananas	Medium
1011-capacity-to-ship-packages-within-d-days	Medium
1373-maximum-sum-bst-in-binary-tree	Hard

Binary Tree

Problem Name	Difficulty
0099-recover-binary-search-tree	Medium
0226-invert-binary-tree	Easy
1373-maximum-sum-bst-in-binary-tree	Hard

Dynamic Programming

Problem Name	Difficulty
0042-trapping-rain-water	Hard
0121-best-time-to-buy-and-sell-stock	Easy
1373-maximum-sum-bst-in-binary-tree	Hard

DP on Trees

Problem Name	Difficulty
1373-maximum-sum-bst-in-binary-tree	Hard

Array

Problem Name	Difficulty
0001-two-sum	Easy
0011-container-with-most-water	Medium
0015-3sum	Medium
0033-search-in-rotated-sorted-array	Medium
0035-search-insert-position	Easy
0042-trapping-rain-water	Hard
0049-group-anagrams	Medium
0074-search-a-2d-matrix	Medium
0121-best-time-to-buy-and-sell-stock	Easy
0128-longest-consecutive-sequence	Medium
0150-evaluate-reverse-polish-notation	Medium
0153-find-minimum-in-rotated-sorted-array	Medium
0167-two-sum-ii-input-array-is-sorted	Medium
0217-contains-duplicate	Easy
0347-top-k-frequent-elements	Medium
0496-next-greater-element-i	Easy
0560-subarray-sum-equals-k	Medium
0704-binary-search	Easy
0739-daily-temperatures	Medium
0875-koko-eating-bananas	Medium
1011-capacity-to-ship-packages-within-d-days	Medium

Hash Table

Problem Name	Difficulty
0001-two-sum	Easy
0003-longest-substring-without-repeating-characters	Medium
0049-group-anagrams	Medium
0128-longest-consecutive-sequence	Medium
0141-linked-list-cycle	Easy
0142-linked-list-cycle-ii	Medium
0217-contains-duplicate	Easy
0242-valid-anagram	Easy
0347-top-k-frequent-elements	Medium
0424-longest-repeating-character-replacement	Medium
0438-find-all-anagrams-in-a-string	Medium
0496-next-greater-element-i	Easy
0560-subarray-sum-equals-k	Medium
0567-permutation-in-string	Medium

Two Pointers

Problem Name	Difficulty
0011-container-with-most-water	Medium
0015-3sum	Medium
0019-remove-nth-node-from-end-of-list	Medium
0042-trapping-rain-water	Hard
0125-valid-palindrome	Easy
0141-linked-list-cycle	Easy
0142-linked-list-cycle-ii	Medium
0167-two-sum-ii-input-array-is-sorted	Medium
0567-permutation-in-string	Medium
2095-delete-the-middle-node-of-a-linked-list	Medium

Sorting

Problem Name	Difficulty
0015-3sum	Medium
0049-group-anagrams	Medium
0217-contains-duplicate	Easy
0242-valid-anagram	Easy
0347-top-k-frequent-elements	Medium

String

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters	Medium
0020-valid-parentheses	Easy
0049-group-anagrams	Medium
0125-valid-palindrome	Easy
0242-valid-anagram	Easy
0424-longest-repeating-character-replacement	Medium
0438-find-all-anagrams-in-a-string	Medium
0567-permutation-in-string	Medium

Divide and Conquer

Problem Name	Difficulty
0347-top-k-frequent-elements	Medium

Heap (Priority Queue)

Problem Name	Difficulty
0347-top-k-frequent-elements	Medium

Bucket Sort

Problem Name	Difficulty
0347-top-k-frequent-elements	Medium

Counting

Problem Name	Difficulty
0347-top-k-frequent-elements	Medium

Quickselect

Problem Name	Difficulty
0347-top-k-frequent-elements	Medium

Union-Find

Problem Name	Difficulty
0128-longest-consecutive-sequence	Medium

Prefix Sum

Problem Name	Difficulty
0560-subarray-sum-equals-k	Medium

Greedy

Problem Name	Difficulty
0011-container-with-most-water	Medium

Stack

Problem Name	Difficulty
0020-valid-parentheses	Easy
0042-trapping-rain-water	Hard
0150-evaluate-reverse-polish-notation	Medium
0225-implement-stack-using-queues	Easy
0496-next-greater-element-i	Easy
0739-daily-temperatures	Medium

Monotonic Stack

Problem Name	Difficulty
0042-trapping-rain-water	Hard
0496-next-greater-element-i	Easy
0739-daily-temperatures	Medium

Sliding Window

Problem Name	Difficulty
0003-longest-substring-without-repeating-characters	Medium
0424-longest-repeating-character-replacement	Medium
0438-find-all-anagrams-in-a-string	Medium
0567-permutation-in-string	Medium

Matrix

Problem Name	Difficulty
0074-search-a-2d-matrix	Medium

Design

Problem Name	Difficulty
0225-implement-stack-using-queues	Easy

Queue

Problem Name	Difficulty
0225-implement-stack-using-queues	Easy

Bracket Sequences

Problem Name	Difficulty
0020-valid-parentheses	Easy

Math

Problem Name	Difficulty
0150-evaluate-reverse-polish-notation	Medium

Linked List

Problem Name	Difficulty
0019-remove-nth-node-from-end-of-list	Medium
0141-linked-list-cycle	Easy
0142-linked-list-cycle-ii	Medium
0206-reverse-linked-list	Easy
0237-delete-node-in-a-linked-list	Medium
2095-delete-the-middle-node-of-a-linked-list	Medium

Recursion

Problem Name	Difficulty
0206-reverse-linked-list	Easy

Floyd's Cycle Finding Algorithm

Problem Name	Difficulty
0141-linked-list-cycle	Easy
0142-linked-list-cycle-ii	Medium

Breadth-First Search

Problem Name	Difficulty
0226-invert-binary-tree	Easy