Help me in solving P4_172 problem

My issue

i tried every single test case in my mind but i did passed the last test case, could anyone share the last test case for this problem, i will really appreciate it.

My code

#include <bits/stdc++.h>
using namespace std;

int main() {
	int t=1;
    cin>>t;
    while(t--)
    {
        string s1,s2;
        cin>>s1>>s2;
        int n=s1.length();
        if(n<s2.length())
        {
            cout<<-1<<endl;
            continue;
        }
        vector<int> v(n);
        int j=s2.length()-1;
        for(int i=n-1;i>=0;i--)
        {
            if(j==-1)  break;
            if(s1[i]==s2[j])
            {
                v[i]=1;
                j--;
            }
        }
        if(j!=-1)
        {
            cout<<-1<<endl;
            continue;
        }
        int sum=0;
        int count=1;
        for(int k:v)
        {
            if(k==0)
            {
                sum+=count;
            }
            else{
                count++;
            }
        }
        cout<<sum<<endl;
    }
    return 0;

}

Problem Link: Transform String Practice Coding Problem

You can see my solution if it’s any help
https://www.codechef.com/viewsolution/1129575370