C语言——实例025 阶乘和

/*Name: Copyright: Author: Date: 30/07/17 21:29Description: 【程序25】 题目：求1+2!+3!+...+20!的和*/#include <stdio.h>int main(){int i,n,a[100];long int sum;while(printf("请输入项数：") && scanf("%d",&n) != EOF){sum = 0;a[1] = 1;for(i = 2;i <= n;i++){a[i] = a[i-1] * i;sum = sum + a[i];}printf("1+2!+3!+...+20! = %ld\n\n",sum+a[1]);}return 0;}