Java圆周率、概率计算

Java简易程式-求圆周率 & 投骰子概率

求圆周率：假设正方形标靶，中有内切圆。正方形边长L=2，内切圆半径r=1;
内切圆和正方形的面积比：πr²/L² = π/4 => 乘以4即为圆周率;
假设 x 与 y 坐标为随机标点，中心点-1--1范围内，即为内切圆面积.

public class Pi{
   public static void main(String[] args){
     int hit   = 0;
     int total = 0; 
     while(true){
       float x = (float)Math.random()*2-1;
       float y = (float)Math.random()*2-1;
       if(x*x + y*y < 1){
       hit++;
       }
       System.out.print((float)hit/(float)total*4.0F);
       total++;
       // 3.1415926
    }        
   }
}

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投方形骰子计算各面出现的概率
设定数组，循环次数，每次随机生成一个0-5的数字，对应数组下标；

public class Dice{
    public static void main(String[] args) {
        int[] dice = new int[6];
        int NUM = 10000;

        for (int i = 0; i < NUM; i++) {
            int number = (int) (Math.random()*5.99999);
            dice[number]++;
        }

        System.out.println("One:" + dice[0] +
                " Two:" + dice[1] +
                " Three:" + dice[2] +
                " Four:" + dice[3] +
                " Five:" + dice[4] +
                " Six" + dice[5]);
    }
}