昨晚喝酒摇骰子，喝了不少酒。为了少喝点写个简单代码计算下摇色子概率。
规则：
1、一点可以当成1点或者其他任意点数。
2、每人蛊中有5个骰子。
3、从低往高叫全场最少有多少个数字num点数。
double p = 0;
while (num <= dice){
p += Math.pow(1 / 6.0, num) * Math.pow(5 / 6.0, dice - num) * arrange(num,dice);
num++;
}
点数大于等于num出现的概率相加。
public class Test {
public static void main(String[] args) {
double p2 = caculateProbability1(6, 8 * 5);
double p1 = caculateProbability1(7, 8 * 5);
//人头一
double p = caculateProbability1(8, 8 * 5);
double p3 = caculateProbability1(9, 8 * 5);
double p32 = caculateProbability2_6(10, 8 * 5);
double p33 = caculateProbability2_6(11, 8 * 5);
double p34 = caculateProbability2_6(12, 8 * 5);
double p35 = caculateProbability2_6(13, 8 * 5);
double p4 = caculateProbability2_6(14, 8 * 5);
double p5 = caculateProbability2_6(15, 8 * 5);
double p6 = caculateProbability2_6(16, 8 * 5);
double p7 = caculateProbability2_6(17, 8 * 5);
//返回叫10-20的概率
double[] pa0 = stragety1(8 * 5,0);
double[] pa1 = stragety1(8 * 5,1);
double[] pa2 = stragety1(8 * 5,2);
double[] pa3 = stragety1(8 * 5,3);
double[] pa4 = stragety1(8 * 5,4);
double[] pa5 = stragety1(8 * 5,5);
//返回叫5-10的概率
double[] pa01 = stragety2_6(8 * 5,0);
double[] pa11 = stragety2_6(8 * 5,1);
double[] pa21 = stragety2_6(8 * 5,2);
double[] pa31 = stragety2_6(8 * 5,3);
double[] pa41 = stragety2_6(8 * 5,4);
double[] pa51 = stragety2_6(8 * 5,5);
System.out.println(p);
}
/**
* 策略概率集合，已有1数字个数
* */
private static double[] stragety1(double dice, double myNum) {
double[] doubles = new double[6];
for (int i = 5; i <= 10; i++) {
doubles[i-5] = Math.round(caculateProbability1(i-myNum,dice-5) * 100)/100.0;
}
return doubles;
}
/**
* 策略概率集合，已有2-6数字个数
* */
private static double[] stragety2_6(double dice, double myNum) {
double[] doubles = new double[11];
for (int i = 10; i <= 20; i++) {
doubles[i-10] = Math.round(caculateProbability2_6(i-myNum,dice-5) * 100)/100.0;
}
return doubles;
}
/**
* 计算骰子出现1点的概率
* */
private static double caculateProbability1(double num, double dice) {
double p = 0;
while (num <= dice){
p += Math.pow(1 / 6.0, num) * Math.pow(5 / 6.0, dice - num) * arrange(num,dice);
num++;
}
return p;
}
/**
* 计算骰子出现2-6点的概率
* */
private static double caculateProbability2_6(double num, double dice) {
double p = 0;
while (num <= dice){
p += Math.pow(2 / 6.0, num) * Math.pow(4 / 6.0, dice - num) * arrange(num,dice);
num++;
}
return p;
}
/**
* 计算排列组合情况
* n 总数
* m 需要排列的元素个数
* */
private static double arrange(double m, double n){
if (m > n/2){
m = n - m;
}
double arrange = 1;
while (m > 0){
arrange *= n / m;
m--;
n--;
}
return arrange;
}
}