codeforce - email from polycarp

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        string a,b,str;
        cin>>a>>b;
        int x=a.size(),y=b.size();
        if(y<x)cout<<"NO"<<endl;
        else
        {
            int i=0,j=0;
            bool f= false;
            while(i<x || j<y)
            {
                if(a[i]==b[j])
                    {
                        str+=b[j];
                        i++,j++;
                    }
                    else
                    {
                        if(a[i-1]==b[j])
                        j++;
                        else
                        {
                            f=true;
                            break;
                        }
                    }
            }
            if(f)cout<<"NO"<<endl;
            else if(str==a)cout<<"YES"<<endl;
            else cout<<"NO"<<endl;
        }
    }
}