/*-------------------------------------------------------
编程计算:s=1!+2!+3!+…n!   (n由键盘输入,使用for循环)
-------------------------------------------------------*/
#include <stdio.h>
main()
{
	int i,j,n;
	long p,sum;
	sum=0;
	printf("请输入一个正整数n:");
	scanf("%d",&n);
/**********Program**********/
	p = 1;
	for( i = 1;i <= n; i++ ){
		p *= i;
		sum += p;
	}

/**********  End  **********/
	printf("1!+2!+...+%d!= %d\n",n,sum);
}