| Problem Name | Online Judge | Contest | Difficulty Level | |
|---|---|---|---|---|
| 1 | Lazy Student | Codeforces | Codeforces Round #335 (Div. 1) & Codeforces Round #335 (Div. 2) | 4 |
| 2 | The Child and Zoo | Codeforces | Codeforces Round #250 (Div. 2) & Codeforces Round #250 (Div. 1) | 4 |
| 3 | Minimum spanning tree for each edge | Codeforces | Educational Codeforces Round 3 | 5 |
| 4 | Hamiltonian Spanning Tree | Codeforces | Wunder Fund Round 2016 (Div. 1 + Div. 2 combined) | 6 |
| 5 | Edges in MST | Codeforces | Codeforces Round #111 (Div. 2) | 7 |