如何模拟掷骰子 3000 次并计算掷双的次数?.JAVA

Question

我是编程世界的新手，所以如果你们中的任何人能帮助我在这方面做得更好，我将不胜感激。我对这个程序的目标是模拟 3000 次掷骰子，并使用 while 循环计算每个不同可能的双打对的双打掷出的次数。结果应打印在对话框中。

   Random random;
   random = new Random();
   diceRolls = 1;
   snakeEyes = 1;
   doubleTwos = 1;
   doubleThrees = 1;
   doubleFours = 1;
   doubleFives = 1;
   doubleSixes = 1;

   while (diceRolls <= finalDiceRoll) {
       int diceRolls = 1;
       int die1 = random.nextInt(6) + 1;
       int die2 = random.nextInt(6) + 1;

       if (die1 == 1 && die2 == 1){
           //snakeEyes = snakeEyes + 1;    
           snakeEyes++;
       }
       else if (die1 == 2 && die2 == 2 ) {
           doubleTwos++;
       }
       else if (die1 == 3 && die2 == 3) {
           doubleThrees++;
       }
       else if (die1 == 4 && die2 == 4) {
           doubleFours++;
       }
       else if (die1 == 5 && die2 == 5) {
           doubleFives++;
       }
       else if (die1 == 6 && die2 == 6) {
           doubleSixes++;
       }
       JOptionPane.showMessageDialog (null, "You rolled snake eyes " + snakeEyes + " timesnYou rolled double twos " + doubleTwos + " timesnYou"
                                     + " rolled double threes " + doubleThrees + " timesnYou rolled double fours " + doubleFours + " timesnYou"
                                     + " rolled double fives " + doubleFives + " timesnYou rolled double sixes " + doubleSixes + " times");
}

我

在这里遇到的问题是，我从该程序中获得的结果似乎并不"合理"。例如，在 3000 个掷骰子中，我得到 1 对每个双打。我做错了什么？

Answer 1

您必须在代码中进行一些更改，

1. 通过 0 初始化所有变量。

2. 将while-loop条件更改为

 while (diceRolls <= finalDiceRoll)  // hoping that finalDiceRoll = 3000

3 从while-loop中删除int diceRolls = 1;，并在while-loop末尾添加diceRolls++;。

4.把你的JOptionPane放在while-loop外面，如果没有，你必须关闭3000次你的JOptionPane dailog。

将这些更改应用于代码后，您将了解自己做错了什么，并且代码将运行良好。

Answer 2

将showMessageDialog移到 while 循环之外并递增diceRolls变量。用 0 初始化所有其他整数变量。
更好(更干净、更短(的方法是使用二维数组或地图。

Random random = new Random();
int snakeEyes = 0;
int doubleTwos = 0;
int doubleThrees = 0;
int doubleFours = 0;
int doubleFives = 0;
int doubleSixes = 0;
int diceRolls = 1;
while (diceRolls <= 3000) {
    int die1 = random.nextInt(6) + 1;
    int die2 = random.nextInt(6) + 1;
    if (die1 == 1 && die2 == 1) {
        snakeEyes++;
    } else if (die1 == 2 && die2 == 2) {
        doubleTwos++;
    } else if (die1 == 3 && die2 == 3) {
        doubleThrees++;
    } else if (die1 == 4 && die2 == 4) {
        doubleFours++;
    } else if (die1 == 5 && die2 == 5) {
        doubleFives++;
    } else if (die1 == 6 && die2 == 6) {
        doubleSixes++;
    }
    diceRolls++;
}
JOptionPane.showMessageDialog(null, "You rolled snake eyes " + snakeEyes + " timesnYou rolled double twos " + doubleTwos + " timesnYou"
        + " rolled double threes " + doubleThrees + " timesnYou rolled double fours " + doubleFours + " timesnYou"
        + " rolled double fives " + doubleFives + " timesnYou rolled double sixes " + doubleSixes + " times");

上述较短版本：

Random random = new Random();
int[] doubled = new int[6];
for (int diceRolls = 0; diceRolls < 3000; diceRolls++) {
    int die1 = random.nextInt(6);
    int die2 = random.nextInt(6);
    if (die1 == die2)
        doubled[die1]++;
}
JOptionPane.showMessageDialog(null, "You rolled snake eyes " + doubled[0] + " timesnYou rolled double twos " + doubled[1] + " timesnYou"
        + " rolled double threes " + doubled[2] + " timesnYou rolled double fours " + doubled[3] + " timesnYou"
        + " rolled double fives " + doubled[4] + " timesnYou rolled double sixes " + doubled[5] + " times");

Answer 3

计数逻辑应如下所示：

doubleTwos = 0;
doubleThrees = 0;
doubleFours = 0;
doubleFives = 0;
doubleSixes = 0;
finalDiceRoll = 3000;
int diceRolls = 0;
while (diceRolls < finalDiceRoll) {
    ++diceRolls;

循环后的任何消息。

使用数组，您可以节省键入：

int[] doubleCounts = new int[6]; // By 0 based dice values
for (int i = 0; i < finalDiceRoll; ++i) {
    int die1 = random.nextInt(6); // With dice values 0-5
    int die2 = random.nextInt(6);
    if (die1 == die2) {
       ++doubleCounts[die1];
    }
}
int snakeEyes = doubleCounts[0];
int doubleTwos = doubleCounts[1];
...

Answer 4

简化。消除重复。当可以使用数组时，不要使用多个变量。

int[] doubles = new int[7]; // make the index the number rolled (ignore index 0)
int diceRolls = 0;
while (diceRolls++ < 3000) {
  int die1 = random.nextInt(6) + 1;
  int die2 = random.nextInt(6) + 1;
  if (die1 == die2)
       doubles[die1]++;
}
String output = "";
for (int i = 1; i <= 6; i++)
    output += "You rolled double " + i + "'s " + doubles[i] + " timesn";
JOptionPane.showMessageDialog (null, output);

这就是您所需要的。