| Problem Name | Online Judge | Contest | Difficulty Level | |
|---|---|---|---|---|
| 1 | D-query | SPOJ | 1 | |
| 2 | Mr. Kitayuta's Colorful Graph | Codeforces | Codeforces Round #286 (Div. 1) & Codeforces Round #286 (Div. 2) & Codeforces Round #286 (Div. 1) & Codeforces Round #286 (Div. 2) | 2 |
| 3 | GCD 2010 | Timus | 3 | |
| 4 | Zero Query | SPOJ | 3 | |
| 5 | Little Elephant and Array | Codeforces | Codeforces Round #136 (Div. 1) & Codeforces Round #136 (Div. 2) | 3 |
| 6 | Powerful array | Codeforces | Yandex.Algorithm 2011 Round 2 | 3 |
| 7 | Gao on a tree | SPOJ | 3 | |
| 8 | XOR and Favorite Number | Codeforces | Codeforces Round #340 (Div. 2) | 4 |
| 9 | Xenia and Tree | Codeforces | Codeforces Round #199 (Div. 2) | 4 |
| 10 | Little Artem and Time Machine | Codeforces | VK Cup 2016 - Round 2 | 5 |
| 11 | Tree and Queries | Codeforces | Codeforces Round #221 (Div. 1) | 5 |
| 12 | DZY Loves Colors | Codeforces | Codeforces Round #254 (Div. 1) & Codeforces Round #254 (Div. 2) | 6 |
| 13 | Holidays | Codeforces | School Team Contest #2 (Winter Computer School 2010/11) | 6 |
| 14 | Ada and Numbering | SPOJ | 6 | |
| 15 | Holes | Codeforces | Codeforces Beta Round #13 | 6 |
| 16 | Serega and Fun | Codeforces | Codeforces Round #260 (Div. 1) | 6 |
| 17 | Counting diff-pairs | SPOJ | 6 | |
| 18 | DZY Loves Fibonacci Numbers | Codeforces | Codeforces Round #255 (Div. 1) & Codeforces Round #255 (Div. 2) | 6 |
| 19 | Subset Sums | Codeforces | Codeforces Round #202 (Div. 1) & Codeforces Round #202 (Div. 2) | 7 |
| 20 | Conveyor Belts | Codeforces | Codeforces Round #278 (Div. 1) | 8 |
| 21 | Ann and Books | Codeforces | Codeforces Round #442 (Div. 2) | 8 |
| 22 | Instant Messanger | Codeforces | Codeforces Round #233 (Div. 1) | 8 |
| 23 | Jeff and Removing Periods | Codeforces | Codeforces Round #204 (Div. 1) | 8 |
| 24 | Destiny | Codeforces | Codeforces Round #429 (Div. 1) | 8 |