【C语言】自学；算出1!+2!+3!+......+20!

#include<stdio.h>
int main()
{
	int s1=1,s2=0;
	for(int n=1;n<=20;n++)
	{
		s1=n*s1;
		s2=s1+s2;
	}
	
	printf("答案：%d",s2);
}