pta** calculates the partial and ** running timeout of the power series expansion

pta title ** Find the part of the power series expansion and ** run timeout

7-15** Find the partial sum of power series expansion **

Input format :
Input gives a real x∈[0,5] in a line.

Output format :
Outputs the partial sum of the power series satisfying the condition in one line, keeping four decimal places.

input sample: < br / > < br / > 1.2 output sample: < br / > < br / > 3.3201 time limit

```c
#include <stdio.h>
#include <math.h>

int main()
{
    double x,xk,sum=1,k=1,i=1;
    scanf("%lf", &x);
    xk=x;
    while (fabs(xk/k)>= 0.00001)
    {

        sum+=xk/k;
        xk*=x;
        i++;
        k*=i;
    }
    sum+=xk/k;
    printf("%.4lf\n", sum);
}

###### 运行内容超时
###### 用一般算阶乘的方法做，还是超时了，我看到有的博主方法跟我的大相径庭但却是对的

```c
#include <stdio.h>
#include <math.h>

int main()
{
    double x,xk,sum=1,k=1,i=1;
    scanf("%lf", &x);
    xk=x;
    while (fabs(xk/k)>= 0.00001)
    {

        sum+=xk/k;
        xk*=x;
        i++;
        k*=i;
    }
    sum+=xk/k;
    printf("%.4lf\n", sum);
}


不能理解，难到for语句运行时间长一些？

Hope you can show me this konnyaku