假定n=2,下列程序的运行结果是。#includeusing namespace std;int fun(int m);void main() {cout << "please input a number :";int n, s = 0;cin >> n;s = fun(n);cout << s << endl;}int fun(int m){int p =1, s = 0;for (int i = 1; i <= m; i ){p *= i;s = p;}return s;}