计算并输出1！+2！+3！....+n!(嵌套循环）

计算并输出1！+2！+3！....+n!(嵌套循环）

#include<stdio.h>

int main()

{

int i, n;

long sum = 0;

long p=1;

printf("Please enter n:");

scanf_s("%d", &n);    //VS里面scanf后面要加_s

for (i = 1; i <= n; i++)

{

p = p * i;        //阶乘

sum = sum + p;      //阶乘的和累加

}

printf("sum= %ld", sum);

return 0;

}