# include <stdio.h>
# include <math.h>
int main ()
{
    int i=1;
    double s=0.0,k=1.0,n=1.0;
    while (fabs(s)>=1e-6)
    {
        s=s+k;
        n=n+2.0;
        i=-i;
        k=i/n;
    }
    s=s*4;
    printf ("s=%10.8f\n",s);
    return 0;
}
    运行结果为4.00000

问题是啥呀？什么状况！！

while的条件应该是fabs（k）

你的问题是不是在求圆周率，

# include <stdio.h>
 # include <math.h>
 int main ()
 {
     int i=1;
     double s=0.0,k=1.0,n=1.0;
     while (fabs(k)>=1e-6)
     {
         s=s+k;
         n=n+2.0;
         i=-i;
         k=i/n;
     }
     s=s*4;
     printf ("s=%10.8f\n",s);
     return 0;
 }
 

同意楼上的