| Problem Name | Online Judge | Contest | Difficulty Level | |
|---|---|---|---|---|
| 1 | Lowest Common Ancestor | SPOJ | 1 | |
| 2 | Query on a tree II | SPOJ | 1 | |
| 3 | Distance Query | SPOJ | 2 | |
| 4 | Ants Colony | URI | 3 | |
| 5 | Lowest Common Ancestor | CodeChef | 3 | |
| 6 | Flea circus | UVA | 3 | |
| 7 | Distance in the Tree | Timus | 3 | |
| 8 | Ants Colony | UVA | 3 | |
| 9 | Design Tutorial: Inverse the Problem | Codeforces | Codeforces Round #270 | 4 |
| 10 | Tree 2 | Timus | 4 | |
| 11 | A and B and Lecture Rooms | Codeforces | Codeforces Round #294 (Div. 2) | 4 |
| 12 | Fools and Roads | Codeforces | Codeforces Round #121 (Div. 1) & Codeforces Round #121 (Div. 2) | 4 |
| 13 | Misha, Grisha and Underground | Codeforces | Codeforces Round #425 (Div. 2) | 5 |
| 14 | Duff in the Army | Codeforces | Codeforces Round #326 (Div. 1) & Codeforces Round #326 (Div. 2) | 5 |
| 15 | FloatingMedian | TopCoder | SRM 310 - Div1 medium - Div2 hard] (9990) | 6 |
| 16 | Turning Turtles | Timus | 7 |