c语言 计算π的近似值?

Question

c语言 计算π的近似值

用π/4=1-1/3+1/5-1/7+1/9-……这条公式来计算，知道某项的绝对值小于10^-6为止

程序如下。

#include <stdio.h>
#include <stdlib.h>
int main()
{  float sum=0.0;int i=1,d=1;
  while(1/i>=1e-6)
  {
      sum=sum+d/i;
      d=d*(-1);
      i=i+2;
  }          
    sum=sum*4;
printf("%10.8f\n",sum);

   system("pause");
   return 0;
}
   

为什么最后显示结果是4.000000 想知道哪里出错了……

Answer 1

#include <stdio.h>#include <stdlib.h>int main(){ &nbsp;float sum=0.0;float i=1,d=1; &nbsp; while(1/i>=1e-6) &nbsp; { &nbsp; &nbsp; &nbsp; sum=sum+d/i; &nbsp; &nbsp; &nbsp; d=d*(-1); &nbsp; &nbsp; &nbsp; i=i+2; &nbsp; } &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sum=sum*4;printf("%10.8f\n",sum); &nbsp; &nbsp;system("pause"); &nbsp; &nbsp;return 0;}输出结果为：3.14159369