LeetCode #1
Easy
Array
15 min
All roadmapsValid Parentheses Merge Two Sorted Lists Best Time to Buy and Sell Stock Valid Palindrome Invert Binary Tree Valid Anagram Binary Search Flood Fill Maximum Subarray Lowest Common Ancestor of a Binary Search Tree Insert Interval 01 Matrix K Closest Points to Origin Balanced Binary Tree Linked List Cycle Implement Queue using Stacks First Bad Version Ransom Note Longest Substring Without Repeating Characters 3Sum Binary Tree Level Order Traversal Clone Graph Evaluate Reverse Polish Notation Course Schedule Implement Trie (Prefix Tree) Coin Change Product of Array Except Self Climbing Stairs Longest Palindrome Min Stack Reverse Linked List Validate Binary Search Tree Number of Islands Rotting Oranges Search in Rotated Sorted Array Combination Sum Permutations Merge Intervals Lowest Common Ancestor of a Binary Tree Time Based Key-Value Store Minimum Window Substring Serialize and Deserialize Binary Tree Trapping Rain Water Find Median from Data Stream Majority Element Add Binary Diameter of Binary Tree Middle of the Linked List Accounts Merge Sort Colors Word Break Partition Equal Subset Sum String to Integer (atoi) Spiral Matrix Subsets Binary Tree Right Side View Longest Palindromic Substring Word Ladder Basic Calculator Maximum Profit in Job Scheduling Merge k Sorted Lists Largest Rectangle in Histogram Maximum Depth of Binary Tree Contains Duplicate Unique Paths Construct Binary Tree from Preorder and Inorder Traversal Container With Most Water Letter Combinations of a Phone Number Word Search Find All Anagrams in a String Minimum Height Trees Task Scheduler LRU Cache Kth Smallest Element in a BST
active
50h estimated75 problemsDSA & Algorithms
Data structures and algorithms tailored for frontend engineers: arrays, trees, graphs, dynamic programming, and the patterns that show up most in FAANG-style coding rounds.
75 questions
75 of 75
Two Sum
LeetCode #20
Easy
Stack
20 min
LeetCode #21
Easy
Linked List
20 min
LeetCode #121
Easy
Array
20 min
LeetCode #125
Easy
String
15 min
LeetCode #226
Easy
Binary Tree
15 min
LeetCode #242
Easy
String
15 min
LeetCode #792
Easy
Binary Search
15 min
LeetCode #733
Easy
Graph
20 min
LeetCode #53
Medium
Dynamic Programming
20 min
LeetCode #235
Easy
Binary Search Tree
20 min
LeetCode #57
Medium
Array
25 min
LeetCode #542
Medium
Graph
30 min
LeetCode #1014
Medium
Heap
30 min
LeetCode #110
Easy
Binary Tree
15 min
LeetCode #141
Easy
Linked List
20 min
LeetCode #232
Easy
Stack
20 min
LeetCode #278
Easy
Binary Search
20 min
LeetCode #383
Easy
Hash Table
15 min
LeetCode #3
Medium
String
30 min
LeetCode #15
Medium
Array
30 min
LeetCode #102
Medium
Binary Tree
20 min
LeetCode #133
Medium
Graph
25 min
LeetCode #150
Medium
Stack
30 min
LeetCode #207
Medium
Graph
30 min
LeetCode #208
Medium
Trie
35 min
LeetCode #322
Medium
Dynamic Programming
25 min
LeetCode #238
Medium
Array
30 min
LeetCode #70
Easy
Dynamic Programming
20 min
LeetCode #409
Easy
String
20 min
LeetCode #155
Medium
Stack
20 min
LeetCode #206
Easy
Linked List
20 min
LeetCode #98
Medium
Binary Search Tree
20 min
LeetCode #200
Medium
Graph
25 min
LeetCode #1036
Medium
Graph
30 min
LeetCode #33
Medium
Binary Search
30 min
LeetCode #39
Medium
Array
30 min
LeetCode #46
Medium
Recursion
30 min
LeetCode #56
Medium
Array
30 min
LeetCode #236
Medium
Binary Tree
25 min
LeetCode #1023
Medium
Binary Search
35 min
LeetCode #76
Hard
String
30 min
LeetCode #297
Hard
Binary Tree
40 min
LeetCode #42
Hard
Stack
35 min
LeetCode #295
Hard
Heap
30 min
LeetCode #169
Easy
Array
20 min
LeetCode #67
Easy
Binary
15 min
LeetCode #543
Easy
Binary Tree
30 min
LeetCode #908
Easy
Linked List
20 min
LeetCode #721
Medium
Graph
30 min
LeetCode #75
Medium
Array
25 min
LeetCode #139
Medium
Trie
30 min
LeetCode #416
Medium
Dynamic Programming
30 min
LeetCode #8
Medium
String
25 min
LeetCode #54
Medium
Matrix
25 min
LeetCode #78
Medium
Recursion
30 min
LeetCode #199
Medium
Binary Tree
20 min
LeetCode #5
Medium
String
25 min
LeetCode #127
Hard
Graph
45 min
LeetCode #224
Hard
Stack
40 min
LeetCode #1352
Hard
Binary Search
45 min
LeetCode #23
Hard
Heap
30 min
LeetCode #84
Hard
Stack
35 min
LeetCode #104
Easy
Binary Tree
15 min
LeetCode #217
Easy
Array
15 min
LeetCode #62
Medium
Dynamic Programming
20 min
LeetCode #105
Medium
Binary Tree
25 min
LeetCode #11
Medium
Array
35 min
LeetCode #17
Medium
Recursion
30 min
LeetCode #79
Medium
Graph
30 min
LeetCode #438
Medium
String
30 min
LeetCode #310
Medium
Graph
30 min
LeetCode #621
Medium
Heap
35 min
LeetCode #146
Medium
Linked List
30 min
LeetCode #230
Medium
Binary Search Tree
25 min