用c语言或者c++编程

Question

用一重循环编程计算s=1！+2！+3！+4！+…+20!

Answer 1

#include<stdio.h>
int main()
{
float s=0,t=1;
int n;
for(n=1;n<=20;n++)
{
t=t*n;
s=s+t;
}
printf("%e\n",s);
return 0;
}