You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

47 lines
542 B

//just have to find nCr in this one.
//long long int can only store till 20!
#include<iostream>
using namespace std;
float fact(int); //ncr will depend on this
float ncr(int, int);
int main()
{
int m, n, r;
cin>>m;
for(int i=0;i<m;i++)
{
cin>>n>>r;
if(r>n)
{
cout<<0<<endl;
continue;
}
else
{
cout<<ncr(n,r)<<endl;
}
}
return 0;
}
float fact(int n)
{
float ret=1;
for(int i=2;i<=n;i++)
{
ret*=i;
}
return ret;
}
float ncr(int n, int r)
{
float res;
res=fact(n)/fact(r)/fact((n-r));
return res;
}