Today I got surprised getting TLE(s) for the problem C of the round #201 (http://mirror.codeforces.com/contest/346/problem/C) during practice. Looks like this problem was caused by stl-vector. Then, I decided to test using my own adjacency list (like the one I usually do for maxflow/mincost) and got ACC. Is it normal vector to be that slow?
stl-vector: http://mirror.codeforces.com/contest/346/submission/4525014
"my"-own-vector: http://mirror.codeforces.com/contest/346/submission/4524990