I have found a really interesting problem http://mirror.codeforces.com/problemset/problem/97/E but i am not able to solve it in the required time complexity. The problem is that given a graph with vertices n and edges m where n,m<=1e5 and you are also given q queries where q<=1e5 and in each query 2 vertices are given u and v. we have to find that whether there exists a simple path with odd length between u and v in each query. Can someone please help me in solving the problem.