Question

求输入一个整数，计算其阶乘，并输出结果,阶乘的计算公式为n!=1x2x....xn

Answer 1

public long Factorial(long n)
{
if(n<0)
MessageBox.Show("参数有误，不能小于0");
if(n == 0)
return 1;
if(n == 1)
return 1;
return Factorial(n - 1) * n;
}
public static void main()
{
System.out.Println("20的阶乘是："+Factorial(20));
}

Answer 2

不知道你需要哪种语言编程，我用了C++
#include<iostream>
using namespace std;
int main()
{
long F(int n);
int N;
cin>>N;
cout<<N<<"!"<<"="<<F(N)<<endl;
return 0;
}
long F(int n)
{
long h;
if(n==1) h=1;
if(n>1)
h=F(n-1)*n;
return h;
}

Answer 3

void main(){
int a,sum=1;
cin>>a;
for(int i=2;i<=a;i++)
sum*=i;
}

Answer 4

#include<iostream>
using namespace std;
int main()
{
long F(int n);
int N;
cin>>N;
cout<<N<<"!"<<"="<<F(N)<<endl;
return 0;
}
long F(int n)
{
long h;
if(n==1) h=1;
if(n>1)
h=F(n-1)*n;
return h;
}