| Maximum Profit in Job Scheduling ↗ | Hard | Array, Binary Search, Dynamic Programming | |
| Palindrome Pairs ↗ | Hard | Array, Hash Table, String | |
| Accounts Merge ↗ | Medium | Array, Hash Table, String | |
| Trapping Rain Water ↗ | Hard | Array, Two Pointers, Dynamic Programming | |
| Alien Dictionary ↗ | Hard | Array, String, Depth-First Search | |
| Contains Duplicate II ↗ | Easy | Array, Hash Table, Sliding Window | |
| Two Sum ↗ | Easy | Array, Hash Table | |
| Add Two Numbers ↗ | Medium | Linked List, Math, Recursion | |
| Cheapest Flights Within K Stops ↗ | Medium | Dynamic Programming, Depth-First Search, Breadth-First Search | |
| Employee Free Time ↗ | Hard | Array, Sweep Line, Sorting | |
| Word Search II ↗ | Hard | Array, String, Backtracking | |
| Valid Parentheses ↗ | Easy | String, Stack | |
| House Robber ↗ | Medium | Array, Dynamic Programming | |
| Contains Duplicate ↗ | Easy | Array, Hash Table, Sorting | |
| Single Number ↗ | Easy | Array, Bit Manipulation | |
| Regular Expression Matching ↗ | Hard | String, Dynamic Programming, Recursion | |
| Happy Number ↗ | Easy | Hash Table, Math, Two Pointers | |
| Maximal Square ↗ | Medium | Array, Dynamic Programming, Matrix | |
| Reverse Bits ↗ | Easy | Divide and Conquer, Bit Manipulation | |
| Add Strings ↗ | Easy | Math, String, Simulation | |
| Basic Calculator II ↗ | Medium | Math, String, Stack | |
| Merge k Sorted Lists ↗ | Hard | Linked List, Divide and Conquer, Heap (Priority Queue) | |
| Convert Sorted Array to Binary Search Tree ↗ | Easy | Array, Divide and Conquer, Tree | |
| Pyramid Transition Matrix ↗ | Medium | Hash Table, String, Backtracking | |
| Minimum Number of Vertices to Reach All Nodes ↗ | Medium | Graph Theory | |
| Design File System ↗ | Medium | Hash Table, String, Design | |
| Mini Parser ↗ | Medium | String, Stack, Depth-First Search | |
| Combination Sum ↗ | Medium | Array, Backtracking | |
| Intersection of Two Linked Lists ↗ | Easy | Hash Table, Linked List, Two Pointers | |
| Text Justification ↗ | Hard | Array, String, Simulation | |
| Detonate the Maximum Bombs ↗ | Medium | Array, Math, Depth-First Search | |
| Minimum Window Substring ↗ | Hard | Hash Table, String, Sliding Window | |
| Subarray Product Less Than K ↗ | Medium | Array, Binary Search, Sliding Window | |
| Design Tic-Tac-Toe ↗ | Medium | Array, Hash Table, Design | |
| All O`one Data Structure ↗ | Hard | Hash Table, Linked List, Design | |
| Maximum Subarray ↗ | Medium | Array, Divide and Conquer, Dynamic Programming | |
| Time Based Key-Value Store ↗ | Medium | Hash Table, String, Binary Search | |
| Can Place Flowers ↗ | Easy | Array, Greedy | |
| Shortest Path in Binary Matrix ↗ | Medium | Array, Breadth-First Search, Matrix | |
| Nth Digit ↗ | Medium | Math, Binary Search | |