题解 | 计算一个数的阶乘

#include <iostream>
using namespace std;

int main() {
    
    int n;
    cin >> n;
    long long factorial = 1;
    
    factorial *= n;
    for (int i = 1; i < n - 1; i ++) {
        factorial *= (n - i);
    }
    

    cout << factorial << endl;
    
    return 0;
}