C语言实现求圆周率

根据PI/4 = 1 - 1/3 +1/5-1/7+1/9.............. 

 

 

#include<stdio.h>
#include<math.h>
void main()
{
 double sum = 1;
 double temp;
 int sign = -1;
 int n = 2;
 float pi;
 while(fabs(temp) > 1e-7)
 {
  temp = (2*n-1)*sign;
  sign = -sign;
  temp = 1/temp;
  sum+=temp;
  n++;
 }
 pi = sum*4;
 printf("圆周率是：%lf/n",pi);
}