| Problem Name | Online Judge | Year | Contest | Difficulty Level | |
|---|---|---|---|---|---|
| 1 | The area of the union of circles | SPOJ | 2 | ||
| 2 | Bridge | Live Archive | 2005 | Asia - Hangzhou | 3 |
| 3 | Timer | Live Archive | 2008 | Asia - Beijing | 4 |
| 4 | Little Mammoth | ZOJ | 4 | ||
| 5 | GM-pineapple | Timus | 4 | ||
| 6 | Volume | Live Archive | 2010 | Asia - Harbin | 5 |
| 7 | Two Cylinders | SGU | 5 | ||
| 8 | Curvy Little Bottles | UVA | 5 | ||
| 9 | Environment Protection | UVA | 6 |