How to find the sum of length of Longest Common Prefixes of all pairs of substrings of a given string. For eg answer for string "aba" is 8. |S|<=1e5.

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.