Java for loop calculate PI

Question

We can approximate p by using the following series: 

PI = 4(1 - 1 / 3 + 1 / 5 - 1 / 7 + 1 / 9 - 1 / 11 + ... + ((-1)i + 1 /  2i - 1))

Write a program that displays the p value for i = 10000, 20000, ..., and 100000 

public class Main {
  public static void main(String[] args) {
    // Compute PI value for i = 10000, 
    double sum = 0;
    double value = 10000.0;
    //your code here

    // Display result
    System.out.println("PI value for i = 100000: " + pi);
  }//w  ww. j  a va 2  s .  c  o m
}





public class Main {
  public static void main(String[] args) {
    // Compute PI value for i = 10000, 
    double sum = 0;
    double value = 10000.0;
    for (double d = 1; d <= (2 * value - 1); d += 2) {
      sum += 1 / d;
      d += 2;
      sum -= 1 / d; 
    }
    double pi = 4 * sum;

    // Display result
    System.out.println("PI value for i = 10000: " + pi);

    // Compute PI value for i = 20000,
    sum = 0;
    value = 20000.0;
    for (double d = 1; d <= (2 * value - 1); d += 2) {
      sum += 1 / d;
      d += 2;
      sum -= 1 / d; 
    }
    pi = 4 * sum;

    // Display result
    System.out.println("PI value for i = 20000: " + pi);

    // Compute PI value for i = 20000,
    sum = 0;
    value = 100000.0;
    for (double d = 1; d <= (2 * value - 1); d += 2) {
      sum += 1 / d;
      d += 2;
      sum -= 1 / d; 
    }
    pi = 4 * sum;

    // Display result
    System.out.println("PI value for i = 100000: " + pi);
  }
}



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