| 2100 |
| Solve |
| Cut | 2100 | Solve |
| Cut Substrings | 2100 | Solve |
| DAG Serialization | 2100 | Solve |
| DNA Evolution | 2100 | Solve |
| Daleks' Invasion (medium) | 2100 | Solve |
| Deconstruction Tree | 2100 | Solve |
| Decryption | 2100 | Solve |
| Degenerate Matrix | 2100 | Solve |
| Desk Disorder | 2100 | Solve |
| Destroy it! | 2100 | Solve |
| Destroying Roads | 2100 | Solve |
| Determine Winning Islands in Race | 2100 | Solve |
| Devu and Birthday Celebration | 2100 | Solve |
| Diadrash (Easy Version) | 2100 | Solve |
| Digits | 2100 | Solve |
| Dispute | 2100 | Solve |
| Distributing Parts | 2100 | Solve |
| Divan and Kostomuksha (easy version) | 2100 | Solve |
| Diverging Directions | 2100 | Solve |
| Divisibility by 25 | 2100 | Solve |
| Domino (hard version) | 2100 | Solve |
| Dormitory | 2100 | Solve |
| Down or Right | 2100 | Solve |