Lab2-Pi

JLab>java Selftest 

JLab> testPi : ok ok ok ok ok ok ok ok ok ok ok ok ok ok ok ok ok ok ok ok  (10.0/10.0)
JLab> : -----------------------------
JLab> : ?????? 10.0 ????? (???? 10.0)
JLab> : -----------------------------
JLab> :<POINT>10.0</POINT> (<TOTAL>10.0</TOTAL> )
JLab>

import java.util.Scanner;

public class Pi {
  // pi1 = 4*(1 - 1/3 + 1/5 - 1/7 + 1/9 - 1/11 + ...)
  // pi2 = 4*(2/3 * 4/3 * 4/5 * 6/5 * 6/7 * 8/7 * ...)
  public static void main(String[] args) {
    Scanner kb = new Scanner(System.in);
    System.out.print("k = ");
    int k = kb.nextInt();

    double pi1 = 0, pi2 = 1.0;
 
    for (int i = 0; i < k; i++) {
      if (i % 2 == 0) {
        pi1 += 1.0 / (i * 2 + 1);
      } else {
        pi1 -= 1.0 / (i * 2 + 1);
      }
      
      pi2 *= (double)((i + 1) / 2 * 2 + 2) / (double)(i / 2 * 2 + 3);
    }
    pi1 *= 4.0;
    pi2 *= 4.0;
    System.out.println("Pi = " + pi1);  // แสดงผลของสูตรแรก
    System.out.println("Pi = " + pi2);  // แสดงผลของสูตรที่สอง
  }

}

SM=0, CM=4, ST=5, KY=361, TR=60:00
ERR = 60:00 ;
ERR = 60:00 ;
ERR = 60:00 ;
ERR = 60:00 ;