跳水比赛 - Java 计划

Question

我正在做一个类似于网站上另一个问题的跳水比赛程序。该程序的目标是要求用户输入潜水员的姓名、七位评委的分数以及潜水的难度等级。输入该信息后，我将根据我的用户创建的 Diver class 创建一个 Diver 对象。然后使用 insertDiver 方法，我应该按照最高的 finalScore 排在第一位的顺序将潜水员添加到潜水员数组中。我不应该对数组进行排序。使用 JOptionPane showMessageDialog 输出，按从最高 finalScore 到最低 finalScore 的顺序显示排名。因为，我将一个数组对象传递给 insertDiver 方法，该数组在该方法完成后就失效了。我尝试将 Diver[] 数组设为全局变量，但结果也不理想。所以最重要的是，我不知道如何通过最高的 finalScore 将潜水员添加到 Divers 数组中，我也不知道如何显示结果。这是我目前的代码：

import javax.swing.JOptionPane;

public class DivingCompetition
{


public static void main(String[] args)
{
  String[] choices = {"Add Diver/Scores", "View Diver Standings", "Search for a diver", "Exit Program"};
  String input = (String) JOptionPane.showInputDialog(null, "What do you want to do?", "Diving Competition", 
                 JOptionPane.QUESTION_MESSAGE, null, choices, choices[0]);
  while(!input.equals("Exit Program"))
  {
     if (input.equals("Add Diver/Scores"))
        addDiver();
     else if (input.equals("View Diver Standings"))
        viewStandings();
     else if (input.equals("Search for a diver"))
        searchDiver();
     else
        System.exit(0);
     input = (String) JOptionPane.showInputDialog(null, "What do you want to do?", "Diving Competition", 
                 JOptionPane.QUESTION_MESSAGE, null, choices, choices[0]);      
  }
}
public static void addDiver()
{
  String scoreInvalid = "The score must be between 0 and 10";
  String difficultyInvalid = "The difficulty must be between 1.2 and 3.8";
  double[] scores = new double[7];
  int i = 0;
  String tempScore = "";
  String tempDifficulty = "";
  double realDifficulty = 0;
  double realScore = 0;
  int numScores = 0;

  String diverName = JOptionPane.showInputDialog("Please enter the diver's name:");
  while (numScores < 7)
  {
     tempScore = JOptionPane.showInputDialog("Please enter the seven judge's scores one at a time");
     realScore = Double.parseDouble(tempScore);
     while (realScore < 0 || realScore > 10)
     {
        JOptionPane.showMessageDialog(null, scoreInvalid, "Invalid Score", JOptionPane.WARNING_MESSAGE);
        tempScore = JOptionPane.showInputDialog("Please enter the corrected score");
        realScore = Double.parseDouble(tempScore);
     }

     scores[i] = realScore;
     i++;
     numScores++;
  }
  tempDifficulty = JOptionPane.showInputDialog("Please enter the difficulty rating of the dive");
  realDifficulty = Double.parseDouble(tempDifficulty);

  while (realDifficulty < 1.2 || realDifficulty > 3.8)
  {
     JOptionPane.showMessageDialog(null, difficultyInvalid, "Invalid Difficulty", JOptionPane.WARNING_MESSAGE);
     tempDifficulty =  JOptionPane.showInputDialog("Please enter the                 corrected difficulty rating of the dive");
     realDifficulty = Double.parseDouble(tempDifficulty);
  }
  Diver aDiver = new Diver(diverName, scores, realDifficulty);
  Diver[] dArray = new Diver[30];
  insertDiver(aDiver, dArray);             
}
public static insertDiver(Diver newElement, Diver[] diverArray)
{
  int addpos = 0;
  int currentSize = 0;

  if (diverArray[addpos] == null)
  {
     diverArray[addpos] = newElement;
     currentSize++;
     addpos++;
  }   
  else
     while (addpos < diverArray.length)
     {
        if (newElement.getFinalScore() > diverArray[addpos].getFinalScore())
        {
           diverArray[addpos] = newElement;
           currentSize++;
           break;
        }   
        else
           addpos++;
     }      
  if (addpos >= diverArray.length)
     diverArray[addpos] = newElement;
  else
  {
     currentSize++;
     for (int i = currentSize - 1; i > addpos; i--)
     {
        diverArray[i] = diverArray[i-1];
        diverArray[addpos] = newElement;
     }           

  }
for (int i = 0; i<diverArray.length; i++)
  {
     System.out.println(diverArray[i]);//just to see the contents of the array printed
  }

}
public static void viewStandings()
{

}
public static void searchDiver()
{

}    
}

这是我创建的 Diver class：

public class Diver
{//begin class

private final double MULTIPLIER = 0.6;
private String diverName;
private double[] scores = new double[7];
private double difficulty, finalScore;
//---------------------------------------------------   
public Diver(String dN, double[] s, double d)
{
  setDiver(dN, s, d);
}
//---------------------------------------------------   
public String getName()
{
  return diverName;
}
//---------------------------------------------------   
public double getDifficulty()
{
  return difficulty;
}
//---------------------------------------------------
public double[] getScores()
{
  return scores;
}
//---------------------------------------------------   
public double getFinalScore()
{
  return finalScore;
}
//---------------------------------------------------   
public String toString()
{
  return "Diver Name: " + diverName + " Judge's Scores: " + scores +
         " Dive Difficulty: " + difficulty;
}
//---------------------------------------------------   
public void setDiverName(String name)
{
  diverName = name.toUpperCase();
}
//---------------------------------------------------   
public void setDifficulty(double diff)
{
   difficulty = diff;
}
//---------------------------------------------------   
public void setScores(double[] sc)
{
   for(int i=0; i < 7; i++)
     scores[i] = sc[i];
}
//---------------------------------------------------   
public void setDiver(String nme, double[] score, double dif)
{
  setDiverName(nme);
  setScores(score);
  setDifficulty(dif);
  computeFinalScore();  
}
//---------------------------------------------------
private void computeFinalScore()
{
  double smallest = scores[0];
  double largest = scores[0];
  double scoreSum = 0;

  for(int i=1; i< scores.length; i++)
  {
     if(scores[i] > largest)
        largest = scores[i];
     else if (scores[i] < smallest)
        smallest = scores[i];                 
  }

  for( double i : scores)
  {
     scoreSum += i;
  }

  finalScore =  (scoreSum - smallest - largest) * difficulty * MULTIPLIER;         
} 
//---------------------------------------------------   
}//end class

Answer 1

程序退出，内存中没有数据可用。要使程序保持运行运行，您必须使用 JFrame 或一般来说是使应用程序保持活动状态的线程。

Answer 2

将这行代码移到您的 class:

的顶部

public class DivingCompetition{
    static Diver[] dArray = new Diver[30];

    public static void main(String[] args){
    etc

虽然这不是最好的解决方案，但它是您实施起来更容易的解决方案。正如您所说，您遇到的问题是在方法完成后数组已经死了，因为局部变量应该在其父代码完成后就死了。如果你像这样声明你的数组，你可以从你的 class.

中的任何地方访问它

要添加更多的Divers，只需在dArray中搜索一个空的地方。

最后，为了使您的代码正常工作，您需要将 insertDiver 方法更改为：

public static void insertDiver(Diver newElement, Diver[] diverArray)

为了在之后放置潜水员，而不是最后对数组进行排序，您必须在添加潜水员时实现一个简单的排序算法：

1)把第一个潜水员放在第一个位置。

2)比较第二个的得分，如果比第一个高，则将第一个车手移到数组末尾，将第二个车手放在第一位。如果没有，就把第二个潜水员放在第二个位置。

3) 随后，对于每一位新潜水员，你要做的是检查他们的分数是否高于数组中其他人的分数，以及是否将那个和所有以前得分较低的潜水员移到一个位置结束，这样他们就可以为得分比他们高的新潜水员赚取space。

f.e。我们想按以下顺序对 [12,45,34,78] 进行排序：

12 -> [null,null,null,null]

45 -> [12,null,null,null]

34 -> [45,12,null,null]

78 -> [45,34,12,null]

      [78,45,34,12]

Answer 3

为 Diver 写一个比较器 Class 然后你可以使用像 TreeSet 这样的集合，这会让你的生活变得轻松一些。
对于显示，您可以使用 JTable。

这里是示例运行代码：

import java.util.Comparator;
import java.util.Set;
import java.util.TreeSet;

import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTable;

public class DivingCompetition
{
    static DiverComparator comp = new DiverComparator();
    static Set<Diver> divers = new TreeSet<Diver>(comp); 

    public static void main(String[] args)
    {
        String[] choices = {"Add Diver/Scores", "View Diver Standings", "Search for a diver", "Exit Program"};
        String input = (String) JOptionPane.showInputDialog(null, "What do you want to do?", "Diving Competition", 
                JOptionPane.QUESTION_MESSAGE, null, choices, choices[0]);
        while(!input.equals("Exit Program"))
        {
            if (input.equals("Add Diver/Scores"))
                addDiver();
            else if (input.equals("View Diver Standings"))
                viewStandings();
            else if (input.equals("Search for a diver"))
                searchDiver();
            else
                System.exit(0);
            input = (String) JOptionPane.showInputDialog(null, "What do you want to do?", "Diving Competition", 
                    JOptionPane.QUESTION_MESSAGE, null, choices, choices[0]);      
        }
    }
    public static void addDiver()
    {
        String scoreInvalid = "The score must be between 0 and 10";
        String difficultyInvalid = "The difficulty must be between 1.2 and 3.8";
        double[] scores = new double[7];
        int i = 0;
        String tempScore = "";
        String tempDifficulty = "";
        double realDifficulty = 0;
        double realScore = 0;
        int numScores = 0;

        String diverName = JOptionPane.showInputDialog("Please enter the diver's name:");
        while (numScores < 7)
        {
            tempScore = JOptionPane.showInputDialog("Please enter the seven judge's scores one at a time");
            realScore = Double.parseDouble(tempScore);
            while (realScore < 0 || realScore > 10)
            {
                JOptionPane.showMessageDialog(null, scoreInvalid, "Invalid Score", JOptionPane.WARNING_MESSAGE);
                tempScore = JOptionPane.showInputDialog("Please enter the corrected score");
                realScore = Double.parseDouble(tempScore);
            }

            scores[i] = realScore;
            i++;
            numScores++;
        }
        tempDifficulty = JOptionPane.showInputDialog("Please enter the difficulty rating of the dive");
        realDifficulty = Double.parseDouble(tempDifficulty);

        while (realDifficulty < 1.2 || realDifficulty > 3.8)
        {
            JOptionPane.showMessageDialog(null, difficultyInvalid, "Invalid Difficulty", JOptionPane.WARNING_MESSAGE);
            tempDifficulty =  JOptionPane.showInputDialog("Please enter the                 corrected difficulty rating of the dive");
            realDifficulty = Double.parseDouble(tempDifficulty);
        }
        Diver aDiver = new Diver(diverName, scores, realDifficulty);

        divers.add(aDiver);
    }
    public static void viewStandings()
    {
        Object[][] rows = new Object[divers.size()][]; 
        int i = 0;
        for(Diver d : divers) {
            rows[i] = new Object[3];
            rows[i][0] = i+1;
            rows[i][1] = d.getName();
            rows[i][2] = d.getFinalScore();
            i++;
        }
            Object[] cols = {
                "Rank","Name","Final Score"
            };
            JTable table = new JTable(rows, cols);
            JOptionPane.showMessageDialog(null, new JScrollPane(table));

    }
    public static void searchDiver()
    {

    }    
}
class DiverComparator implements Comparator<Diver> {

    @Override
    public int compare(Diver o1, Diver o2) {

        // TODO Auto-generated method stub
        return (int) (o2.getFinalScore() - o1.getFinalScore());
    }

}

跳水比赛 - Java 计划

Diving Competition - Java Program

java

arrays

joptionpane