I am having problem with this problem. http://mirror.codeforces.com/problemset/problem/119/D [](http://mirror.codeforces.com/problemset/problem/119/D)

Here is my solution , http://ideone.com/2Cz6rV [](http://ideone.com/2Cz6rV)

I don't know why it gives me WA on test case 36. the test case is big so i can't debug it. Can anybody tell me what's the problem. I am using Z algorithm.

The Idea is, (two string is concatenated with '\x7F' hexadecimal value) 1. Calculate z value for b+a ==> value goes to zba 2. Calculate z value for a+reverse(b) ==> value goes to zarb 2. Calculate z value for reverse(a)+b ==> value goes to zrab

then iterate through zba( from b.size()+1 to the end ) Calculate (i,j) stated in the problem. Check (0...i) string from zarb[] and check (j..n-1) from zrab[].