如何用C语言计算1！+2！+·····n!值

1、用for循环来计算#include<stdio.h>int main(){int n,b,c,x,y;y=0;printf("请输入一个数：");scanf("%d",&n);for(b=1;b<n+1;b++){for(c=1,x=1;c<=b;c++)x=x*c;y=y+x;}printf("1！+2！+·····%d!的值为：%d\n",n,y);return 0;}