I was solving this question: http://www.hackerearth.com/problem/algorithm/comrades-i-3/description/
My code is pretty straightforward. All I have used is a BFS from x to y. It is showing TLE. I don’t understand how to use DFS for this problem as the problem tag says so 
My code:
#include<iostream>
#include<vector>
#include<algorithm>
#include<queue>
#include<stack>
using namespace std;
int main()
{
int t;
scanf("%d",&t);
while(t--) {
int n;
scanf("%d",&n);
vector<int> adjlist[n];
int x1;
for(int i = 0;i < n;i++) {
scanf("%d",&x1);
x1--;
adjlist[i].push_back(x1);
}
int q;
scanf("%d",&q);
while(q--) {
int dis[n];
for(int i = 0;i < n;i++) dis[i] = -1;
int x,y;
scanf("%d %d",&x,&y);
x--;y--;
dis[x] = 0;
queue<int> bfs;
bfs.push(x);
while(bfs.size() > 0) {
int node = bfs.front();
bfs.pop();
if(node == y) break;
int d = dis[node];
for(int i = 0;i < adjlist[node].size();i++) {
if(dis[adjlist[node].at(i)] == -1) {
dis[adjlist[node].at(i)] = d+1;
bfs.push(adjlist[node].at(i));
}
}
}
if(dis[y] == -1) printf("%d\n",dis[y]);
else printf("%d\n",dis[y]-1);
}
}
return 0;
}