2023/4/15

计算n的阶乘

#include<iostream>
using namespace std;
unsigned fac(unsigned n)
{

unsigned f;
if (n==0)
f=1;
else
{
f=fac(n-1)*n;
}
return f;
}
int main()
{

unsigned n;
cin>>n;
unsigned y=fac(n);
cout<<n<<"!="<<y<<endl;
return 0;
}