用C语言编写程序计算圆周率

Sure, I can help you with that! Here is a simple program written in C language to calculate the value of pi:

#include <stdio.h>

int main() {
  int i, n = 10000;
  double pi = 0.0;

  for (i = 0; i < n; i++) {
    pi += 4.0 / (1.0 + i * i);
  }

  printf("The value of pi is approximately: %.15f\n", pi/n);
  return 0;
}

This program uses the Leibniz formula for pi to calculate its value. The more iterations you run, the more accurate the result will be.