Help me in solving INSTDUM problem

My issue

what is wrong here?

My code

#include <iostream>
using namespace std;

int main() {
	int z;
	cin>>z;
	for(int i=0;i<z;i++){
	    
	    int n;
	    cin>>n;
	    int arr[n];
	    
	    for(int i=0;i<n;i++){
	    cin>>arr[i];    
	    }
	    
	    
	    
	    int sum=0;
	    int ans=0;
	    for(int i=0;i<n;i++){
	        
	        sum+=arr[i];
	        int b=i+1;
	  
	          if(((sum/b)*100)==100){
	              ans = ans + 1;
	              
	          }
	  
	  
	  
	    }
	    
	    cout<<ans<<endl;
	    
	    
	    
	    
	    
	}
	return 0;
}

Problem Link: INSTDUM Problem - CodeChef

@shihrshsin
Just take sum and b as float.