SP49 HAREFOX - Hares and Foxes

[SP49 HAREFOX - Hares and Foxes]
(https://www.spoj.com/problems/HAREFOX/11)

I encountered some difficulties in solving this problem. My code can pass the example, but I can’t get AC.
This is my code. Who can help me?
Thank you for your reading and help.

#include<bits/stdc++.h>
using namespace std;
long double n,a,b,c,d,h,f,hy,fy;
int main(){
    cin>>n;
	    for(int i=1;i<=n;i++){
	    scanf("%llf%llf%llf%llf%llf%llf",&a,&b,&c,&d,&h,&f);
	    hy=h,fy=f;
	    hy=a*h-b*f,fy=c*f+d*h;
	    if(hy==fy) cout<<"Ecological balance will develop."<<endl;
	    else if(hy<0&&fy>0) cout<<"Hares will die out while foxes will overgrow."<<endl;
	    else if(hy>0&&fy<0) cout<<"Hares will overgrow while foxes will die out."<<endl;
	    else if(hy<0&&fy<0) cout<<"Both hares and foxes will die out."<<endl;
	    else if(hy>0&&fy>0) cout<<"Both hares and foxes will overgrow."<<endl;
	    else cout<<"Chaos will develop."<<endl;  		
    }
    return 0;
}

Sample input:
2
2 0.5
0.5 0.6
2 3

0.1 1
2 0.1
1 1

Sample output:
Both hares and foxes will overgrow.
Hares will die out while foxes will overgrow.