Run Time error,even though output is right

general
,
1

So For this particular problem, : CONFLIP Problem - CodeChef

I wrote this code:

#include <iostream>
using namespace std;

int main() {
	int T;
	cin>>T;
	while((T--)&&T<=10){
	    int g;
	    cin>>g;
	    
	    while((g--)&&(g<=2000)){
	        int initial,rounds,predict;
	        cin>>initial>>rounds>>predict; ///i,n,q resp
	        int coins[rounds];
	        
	        if(initial==1){ /// if all are to be heads, fill them up all with 1s.
	            for(int i=0;i<rounds;i++){
	                coins[i]=1;
	            }
	        }
	        else if(initial==2){ // if all are to be tails, fill them up all with 2s.
	            for(int i=0;i<rounds;i++){
	                coins[i]=2;
	            }
	        }
	        for(int i=0;i<rounds;i++){ // first i=0, j=0, so if c[i]=1,make it 2.
	            for(int j=0;j<=i;j++){
	                if(coins[j]==1) coins[j]=2;
	                
	                else if(coins[j]==2) coins[j]=1;
	                
	            }
	        }
	        
	        int heads=0,tails=0;
	        
	        for(int i=0;i<rounds;i++){
	            coins[i]==1?heads++:tails++;
	        }
	        
	        predict==1?cout<<heads<<endl:cout<<tails<<endl;
	    }
	    
	    
	}
}

It says : Runtime error (OTHER), but my code prints the output as per the given sample input.