Question

//creates SevenTally class
public class SevenTally{

    private int count;

    public SevenTally(int diceCount){
        this.count = diceCount;
    }

    //creates experiment method
    public boolean experiment(){
        int winCount = 0;
        //creates array of dice rolled according to input
        int[] diceRolls = new int[count];
        //assigns random value from 1 to 6 to each array value
        for(int x = 0; x < diceRolls.length; x++) {
            diceRolls[x] = (1 + (int)(6 * Math.random()));
            for(int n = 0; n < diceRolls.length; n++) {
                for(int m = n + 1; m < n; m++){
                    //checks for two dice in the total rolls that sum to 7
                    if (diceRolls[n] + diceRolls[m] == 7)
                        winCount++;
                }
            }
        }
        if (winCount > 0)
            return true;
        else
            return false;
    }
}

似乎问题在于循环数组。我只测试了代码的那一部分，它正确地将值输入到我的数组中，但是当我将整个事物放在一起时，我认为数组在退出循环后保持为空或清空。

这是类驱动程序：

import java.util.Scanner;

public class SevenDriver{    

    public static void main(String[] args){      
        System.out.println("Enter number of dice to toss");     
        Scanner s = new Scanner(System.in);      
        int diceCount = s.nextInt(); 
        SevenTally t = new SevenTally(diceCount);
        int experiments = 1000000;
        int wins = 0;

        for(int j = 0; j < experiments; j++)
            if(t.experiment()) wins++;

        System.out.println((double)wins/experiments);
    } 
}

Answer 1

你写了

for(int m = n + 1; m < n; m++)

当m从n+1开始，并且循环应该在m<n时运行时，那就没什么可做的了。这应该工作：

for(int m = n + 1; m < diceRolls.length; m++)

为什么输出总是0.0？

1 个答案: