#include<bits/stdc++.h>
using namespace std;
int main()
{
int n,m,i,c,t;
double a,b,sum,cg,cr;
cin>>n;
for(i=0;i<n;i++)
{
cin>>m;
sum=0;
cr=0;
c=0;
for(int j=0;j<m;j++)
{
cin>>a>>b;
if(a>=80&&a<=100)
{
cg=4.00;
}
else if(a>=75&&a<80)
{
cg=3.75;
}
else if(a>=70&&a<75)
{
cg=3.50;
}
else if(a>=65&&a<70)
{
cg=3.25;
}
else if(a>=60&&a<65)
{
cg=3.00;
}
else if(a>=55&&a<60)
{
cg=2.75;
}
else if(a>=50&&a<55)
{
cg=2.50;
}
else if(a>=45&&a<50)
{
cg=2.25;
}
else if(a>=40&&a<45)
{
cg=2.00;
}
else if(a<40&&a>=0)
{
c++;
}
cr+=b;
sum+=cg*b;
}
if(c>0)
{
if(c==1)
cout<<"Case "<<i+1<<": "<<"Sorry, you have failed in "<<1<<" courses!"<<endl;
else
cout<<"Case "<<i+1<<": "<<"Sorry, you have failed in "<<c<<" courses!"<<endl;
}
else
{
cout<<"Case "<<i+1<<": "<<fixed<<setprecision(2)<<sum/cr<<endl;
}
}
}
what’s the problem this code?