I participated in ACM-ICPC regionals back in November and it was a lot of fun. I definitely recommend it to anyone that has the chance to go to preliminaries next year.<p>The time limits are quite brutal for some of the problems @ finals, most of them I'd never have a proper optimal solution for.<p>Also, the fact that Peking understood and solved A in just 5 minutes is crazy. Sure, I could at least do A, but they practice enormously just for these.