C Program to Calculate Value of PI using Leibniz Formula

#include<stdio.h>
#include<conio.h>
#include<math.h>

int main()
{
 long int i, n;
 double sum=0.0, term, pi;
 
 printf("Enter number of terms: ");
 scanf("%ld", &n);

 /* Applying Leibniz Formula */
 for(i=0;i< n;i++)
 {
  term = pow(-1, i) / (2*i+1);
  sum += term;
 }
 pi = 4 * sum;

 printf("\nPI = %.6lf", pi);
 
 return 0;
}

Output

Enter number of terms: 1000000

PI = 3.141592