Help me in solving MANYSUMS problem

help
,
1

My issue

why my code giving runtime error though my answers are correct in the run

My code

#include <iostream>
using namespace std;

int factorial(int n) {
    if (n == 0 || n == 1) {
        return 1;
    } else if (n > 0) {
        int product = 1;
        for (int i = 1; i <= n; i++) {
            product*= i;
        }
        return product;
        
    }
}

int main() {
    int ncr,T,L,R;
    cin>>T;
    for(int i=0;i<T;i++){
    cin>>L>>R;
     ncr= (factorial(R)/(factorial(L)*factorial(R-L)));
     cout<<ncr<<endl;}
}

Learning course: Level up from 1* to 2*
Problem Link: CodeChef: Practical coding for everyone

3

int factorial(int n) {
if (n == 0 || n == 1) {
return 1;
}
int product = 1;
for (int i = 1; i <= n; i++) {
product*= i;
}
return product;
}

4

i guess i wrote the same thing