| Problem | Concept | Level | Frequency |
| Top K Frequently Mentioned Keywords | Priority Queue | Easy | |
| Zombie in Matrix | Graph DFS | Medium | |
| Critical Routers | Graph DFS | Hard | |
| Product Suggestions | Hard | ||
| Number of Clusters | Graph DFS | Hard | |
| Reorder Data in Log Files | Medium | ||
| Partition Labels | Medium | ||
| Longest Palindromic Substring | Dynamic Programming | Easy | |
| Copy List with Random Pointer | Linked list | Easy | |
| Merge Two Sorted Lists | Linked list | Medium | |
| Search a 2D Matrix II | Binary Search Algorithm | Medium | |
| Spiral Matrix | Medium | ||
| Merge Intervals | Hard | ||
| Longest string without 3 consecutive characters | Sliding window | Hard | |
| Zigzag traversal of a tree | Binary Tree | Easy | |
| Combination of words which form other words | Meidum | ||
| Group Shifted Strings | Medium | ||
| Course Schedule | Graphs Topological | Easy | |
| Critical Connections | Graph DFS | Hard | |
| Number of Islands | Graph DFS | Hard |