Question

所以我需要创建一个直方图，显示4个骰子的总和的结果。该程序每次滚动时都会获取骰子的总数。我需要在骰子滚动循环中创建每个数字频率的直方图。这是我的代码：

import java.util.Scanner;
import java.util.Random;
import java.util.Scanner;
import java.lang.Math;
public class DieSimulator
{
public static void main(String[] args)
{
  Die d1 = new Die(6);
  Die d2 = new Die(6);
  Die d3 = new Die(6);
  Die d4 = new Die(6);
  int roll = 100;


  int [] rolls = new int[roll];

     int four = 0;
     int five = 0;
     int six = 0;
     int seven = 0;
     int eight = 0;
     int nine = 0;
     int ten = 0;
     int eleven = 0;   
     int twelve = 0;
     int thirteen = 0;
     int fourteen = 0;
     int fifteen = 0;
     int sixteen = 0;
     int seventeen = 0;
     int eighteen = 0;
     int nineteen = 0;
     int twenty = 0;
     int twentyone = 0;
     int twentytwo = 0;
     int twentythree = 0;
     int twentyfour = 0;

  for (int i=0; i < rolls.length; i++)
{
     int n1 = d1.cast();
     //System.out.print(n1 + "");
     int n2 = d2.cast();
     //System.out.print(n2 + "");
     int n3 = d3.cast();
     //System.out.print(n3 + "");
     int n4 = d4.cast();

     int sum = n1 + n2 + n3 + n4;

     if (sum == 4)
         four++;
     if (sum == 5)
         five++;
     if (sum == 6)
         six++;
     if (sum == 7)
         seven++;
     if (sum == 8)
         eight++;
     if (sum == 9)
         nine++;
     if (sum == 10)
         ten++;
     if (sum == 11)
         eleven++;
     if (sum == 12)
         twelve++;
     if (sum == 13)
        thirteen++;
     if (sum == 14)
        fourteen++;
     if (sum == 15)
        fifteen++;
     if (sum == 16)
        sixteen++;
     if (sum == 17)
        seventeen++;
     if (sum == 18)
        eighteen++;
     if (sum == 19)
        nineteen++;
     if (sum == 20)
        twenty++;
     if (sum == 21)
        twentyone++;
     if (sum == 22)
        twentytwo++;
     if (sum == 23)
        twentythree++;
     if (sum == 24)
        twentyfour++;

     System.out.println("Total Dice roll: " + sum);
     System.out.println(twenty);
     }

     int[] histogram = new int[20];


     System.out.print(histogram);


   }


}

我用什么代码来创建直方图？

Answer 1

更改为这样的数组。可以使用SparseArray，因为索引0,1,2,3从未使用过，但对我来说似乎不值得。我使数组25长（24 + 1），因此结果[x]保持x的骰子滚动发生的次数。

import java.util.Scanner;
import java.util.Random;
import java.util.Scanner;
import java.lang.Math;
public class DieSimulator
{
public static void main(String[] args)
{
  Die d1 = new Die(6);
  Die d2 = new Die(6);
  Die d3 = new Die(6);
  Die d4 = new Die(6);
  int roll = 100;


  int [] rolls = new int[roll];
  int [] results = new int[25];


  for (int i=0; i < rolls.length; i++)
{
     int n1 = d1.cast();
     //System.out.print(n1 + "");
     int n2 = d2.cast();
     //System.out.print(n2 + "");
     int n3 = d3.cast();
     //System.out.print(n3 + "");
     int n4 = d4.cast();

     int sum = n1 + n2 + n3 + n4;
     results[sum]++;

     System.out.println("Total Dice roll: " + sum);
     }

     System.out.print(results);
   }
}

Answer 2

补充RobP的答案，要获得直方图，请在主要功能结束前添加：

for(int i = 4; i < 24; i++) { 
    System.out.println("Result: " + i + " has got " + results[i] + " hit(s)");
}

我还注意到您没有访问rolls数组。您只需使用其大小来限制您的迭代次数。

for (int i = 0; i < 100; i++)

会做同样的事情......而不是在内存中分配数组。

创建直方图数组

2 个答案: