用c语言main函数形式编写

编写自定义函数求s＝x＋x/(12)＋x/(123)+...+x/(123...*n)

#include <stdio.h>
double sum(int x, int n){
    double sum = 0;
    long fact = 1;
    for(int i=1;i<=n;i++){
        fact*=i;
        sum+=(x*1.0/fact);
    }
    return sum;
}
int main()
{
    int x,n;
    scanf("%d %d",&x,&n);
    printf("%lf", sum(x,n));
    return 0;
}