fork download 
  1. import java.math.BigInteger;
  2.  
  3. class Ideone
  4. {
  5.     public static void main(String[] args)
  6.     {
  7.         System.out.println(hage(30));
  8.         System.out.println(calcBirthdayProblemProbability(30));
  9.     }
  10.  
  11.     // 倍精度適当計算精度が足りない
  12.     static double hage(int n)
  13.     {
  14.         double d = 1.0;
  15.         for (int i = 0; i < n; i++)
  16.         {
  17.             d *= (365 - i) / 365d;
  18.         }
  19.         return 1.0 - d;
  20.     }
  21.  
  22.     static String calcBirthdayProblemProbability(int n)
  23.     {
  24.         BigInteger numerator = BigInteger.ONE;
  25.         for (int i = 0; i < n; i++)
  26.             numerator = numerator.multiply(BigInteger.valueOf(365 - i));
  27.  
  28.         BigInteger denominator = BigInteger.valueOf(365).pow(n);
  29.  
  30.         BigInteger probability = denominator.subtract(numerator);
  31.  
  32.         BigInteger gcd = denominator.gcd(probability);
  33.         return String.format("%d / %d", probability.divide(gcd), denominator.divide(gcd));
  34.     }
  35. }
  36.  
Success #stdin #stdout 0.04s 320576KB
comments (?)
stdin 
Standard input is empty
stdout 
0.7063162427192688
9155292769247515688463664204581601330417463671119878183963440529188469 / 12962030625262519859085092767427552277425499342208403503894805908203125
https://ideone.com/Qmn3oZ
language:
Java (HotSpot 12)
created:
9 years ago
visibility:
secret

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!