这个代码应该怎么写呢，写了好久写不出1234.56789

Question

 

Answer 1

供参考：

#include<stdio.h>

int main()
{
    int    i=1,k=1;
    double s=1.0;
    while(i<=18){
            k*=3;
            k = -k;
            s += (double)k/(2*i+1);
            i++;
    }
    printf("s=%.5f\n",s);
    
    return 0;
}