| 1359 | Count All Valid Pickup and Delivery Options | Hard |
| 1420 | Build Array Where You Can Find The Maximum Exactly K Comparisons | Hard |
| 1425 | Constrained Subsequence Sum | Hard |
| 1458 | Max Dot Product of Two Subsequences | Hard |
| 1489 | Find Critical and Pseudo-Critical Edges in Minimum Spanning Tree | Hard |
| 1531 | String Compression II | Hard |
| 1601 | Maximum Number of Achievable Transfer Requests | Hard |
| 1719 | Number Of Ways To Reconstruct A Tree | Hard |
| 1751 | Maximum Number of Events That Can Be Attended II | Hard |
| 1761 | Minimum Degree of a Connected Trio in a Graph | Hard |
| 1851 | Minimum Interval to Include Each Query | Hard |
| 1879 | Minimum XOR Sum of Two Arrays | Hard |
| 1964 | Find the Longest Valid Obstacle Course at Each Position | Hard |
| 1970 | Last Day Where You Can Still Cross | Hard |
| 2009 | Minimum Number of Operations to Make Array Continuous | Hard |
| 2050 | Parallel Courses III | Hard |
| 2092 | Find All People With Secret | Hard |
| 2147 | Number of Ways to Divide a Long Corridor | Hard |
| 2251 | Number of Flowers in Full Bloom | Hard |
| 2392 | Build a Matrix With Conditions | Hard |
| 2444 | Count Subarrays With Fixed Bounds | Hard |
| 2454 | Next Greater Element IV | Hard |
| 2551 | Put Marbles in Bags | Hard |
| 2642 | Design Graph With Shortest Path Calculator | Hard |
| 2742 | Painting the Walls | Hard |
| 2751 | Robot Collisions | Hard |
| 2790 | Maximum Number of Groups With Increasing Length | Hard |