I am not able to figure out what is wrong in my code, even the code in an editorial in not passing all cases
#include <bits/stdc++.h>
using namespace std;
long long int ncr(int n,int r){
long long int ans=1;
int a=max(r,n-r);
for(int i=n;i>a;iā){
ans*=i;
ans/=(n-i+1);
}
return ans;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t; cin>>t;
while(t--){
// your code goes here
int n,k;cin>>n>>k;
cout<<ncr(n-1,k-1)<<endl;
}
return 0;
}