/*用1+1/1!+1/2!+…+1/n!计算e的近似值*/
#include<stdio.h>
void main(){
	int n, i, m;
	double sum,h;
	printf("enter a number:");
	scanf_s("%d", &n);
	m = 1; sum = 1;
	//if (n < 34&&n>8){
		for (i = 1; i <= n; i++){
			m = m*i;
			h = 1.0 / m;
			sum = sum + h;
		}
		printf("%lf", sum);
	//}
	//else
	//	printf("输入的数太大或太小，请重新输入");
	getchar();
	getchar();
}