RunTime Error on online compilers when using string in c++ - c++

Question

I am trying to run this code on online compilers and it shows Runtime errors while it runs perfectly locally. The parts of code that are not being used have been commented out.
#include <iostream>
#include <string>
#include <cmath>
using namespace std;
int main() {
// your code goes here
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
int t;
cin>>t;
while(t--)
{
string s;
cin>>s;
int x,y;
cin>>x>>y;
string ans;
int noOfApple=0,noOfBanana=0;
for(int i=0;i<s.size();i++)
{
if(s[i]=='a')
{
noOfApple++;
}
else
{
noOfBanana++;
}
}
int noOfABlock=ceil(noOfApple/x);
//int noOfBBlock=ceil(noOfBanana/y);
int length=floor(noOfBanana/(noOfABlock-1));
int remainderB=noOfBanana%(noOfABlock-1);
int counter=0;
//condition for '*'
if(noOfBanana<(noOfABlock-1))
{
int q=noOfBanana;
for(int i=0;i<(noOfABlock-1);i++)
{
for(int j=0;j<x;j++)
{
ans[counter++]='a';
}
if(q>0)
{
ans[counter++]='b';
q--;
}
else
{
ans[counter++]='*';
}
}
for(int i=0;i<x;i++)
{
ans[counter++]='a';
}
}
else{
for(int i =0;i<(noOfABlock-1);i++)
{
for(int j=0;j<x;j++)
{
ans[counter++]='a';
}
for(int j=0;j<length;j++)
{
ans[counter++]='b';
}
while(remainderB>0)
{
remainderB--;
ans[counter++]='b';
}
}
for(int i=0;i<x;i++)
{
ans[counter++]='a';
}
}
cout<<ans<<endl;
}
return 0;
}
Input for this program:-
6
ab
1 1
aab
1 1
aabb
1 2
aaaaab
2 1
aaaa
1 3
aaaaa
2 2
When Arrays are used we have to initialize the size of the arrays as they are static but as string are dynamic we do not need to initialize with a size.