Leetcode 62: Unique Paths - binomial coefficient

leetcode_62d.cpp

#include <iostream>

using namespace std;

double factorial(int n) {
    int fact = 1;
    for (int i=2; i<=n; ++i)
        fact *= i;
    return fact;
}

int uniquePath(int m, int n) {
    if (m==0 || n==0)
        return 0;
    int routes = factorial((m-1)+(n-1))/(factorial(m-1)*factorial(n-1));
    return routes;
}

int main() {
    cout << uniquePath(23,12) << "\n";
    return 0;
}