Question

我在关联两个数组的索引时遇到了一些问题，我似乎无法弄明白。例如，我有一个

ID数组{365,222,306,203,113,208,213}

和

得分数组{265,262,257,256,253,246,246}

他们完美匹配：ID [0]与得分[0]匹配，

任务：是将21对数字（ID号和分数）分别读入两个独立的数组。写出配对的数字，并按列标题从高到低排名。

到目前为止，我已经能够按降序成功打印分数，但无法将它们与正确的ID号成功关联。

感谢任何帮助。

到目前为止，这是我的代码：

import java.util.Scanner;
import java.io.*;
import java.util.Arrays;
public class Program408a 
{
    public static void main(String[]args)throws Exception
    {
        Scanner input = new Scanner(new File("C:\\Users\\humza\\Documents\\Eclipse Projects\\Projects\\src\\prg408a.dat"));
        Scanner input1 = new Scanner(new File("C:\\Users\\humza\\Documents\\Eclipse Projects\\Projects\\src\\prg408a.dat"));
        System.out.println("ID\tScore");
        int count = 0;
        while(input.hasNextInt())
        {
            count++;
            input.nextLine();
        }   
        int[] iD = new int [count];
        int[] scores = new int[count];
        for(int i = 0; i < count; i++ )
        {
            iD[i] = input1.nextInt();
            scores[i] = input1.nextInt();
        }
        int[] iDCopy = new int[count];
        int[] scoresCopy = new int[count];
        System.arraycopy(iD, 0, iDCopy, 0, iD.length);
        System.arraycopy(scores, 0, scoresCopy, 0, scores.length);
        System.out.println(Arrays.toString(iD));        
        System.out.println(Arrays.toString(scores));                
        int max = scores[0];                
        int index = 0;      
        for(int i = 0; i < count; i++)
        {
            if(max <= scores[i])
            {
                max = scores[i];    
                index = i;
            }               
        }                   
        for (int i = 0; i < count; i++)
        {
            for (int x = i + 1; x < count; x++)
            {
                if (scoresCopy[i] < scoresCopy[x])
                {
                    int holder = scoresCopy[i];
                    scoresCopy[i] = scoresCopy[x];
                    scoresCopy[x] = holder;  
               }
            }
        }
        System.out.println(Arrays.toString(iDCopy));
        System.out.println(Arrays.toString(scoresCopy));            
    }       
}

Answer 1

进行排序时，只需对iD数组进行相同的更改：

...
int holder = scoresCopy[i];
int iDholder = iDCopy[i];
scoresCopy[i] = scoresCopy[x];
iDCopy[i] = iDCopy[x];
scoresCopy[x] = holder;
iDCopy[x] = iDholder;  
...

顺便说一下，使用两个独立的数组是FORTRAN的做事方式。在现代编程语言中，您可以将两个数字组合成一个结构/记录/类，然后只使用一个数组作为元素。

Answer 2

在交换 scoresCopy 的索引时，您应该交换 iDCopy 的索引。

在代码中进行此更改

for (int i = 0; i < count; i++)
{
    for (int x = i + 1; x < count; x++)
    {
        if (scoresCopy[i] < scoresCopy[x])
        {
            int holder = scoresCopy[i];
            scoresCopy[i] = scoresCopy[x];
            scoresCopy[x] = holder;

            holder = iDCopy[i];
            iDCopy[i] = iDCopy[x];
            iDCopy[x] = holder;
        }
    }
}

新代码应如下所示

import java.util.Scanner;
import java.io.*;
import java.util.Arrays;
public class Program408a 
{
    public static void main(String[]args)throws Exception
    {
        Scanner input = new Scanner(new File("C:\\Users\\humza\\Documents\\Eclipse Projects\\Projects\\src\\prg408a.dat"));
        Scanner input1 = new Scanner(new File("C:\\Users\\humza\\Documents\\Eclipse Projects\\Projects\\src\\prg408a.dat"));
        System.out.println("ID\tScore");
        int count = 0;
        while(input.hasNextInt())
        {
            count++;
            input.nextLine();
        }   
        int[] iD = new int [count];
        int[] scores = new int[count];
        for(int i = 0; i < count; i++ )
        {
            iD[i] = input1.nextInt();
            scores[i] = input1.nextInt();
        }
        int[] iDCopy = new int[count];
        int[] scoresCopy = new int[count];
        System.arraycopy(iD, 0, iDCopy, 0, iD.length);
        System.arraycopy(scores, 0, scoresCopy, 0, scores.length);
        System.out.println(Arrays.toString(iD));        
        System.out.println(Arrays.toString(scores));                
        int max = scores[0];                
        int index = 0;      
        for(int i = 0; i < count; i++)
        {
            if(max <= scores[i])
            {
                max = scores[i];    
                index = i;
            }               
        }                   
        for (int i = 0; i < count; i++)
        {
            for (int x = i + 1; x < count; x++)
            {
                if (scoresCopy[i] < scoresCopy[x])
                {
                    int holder = scoresCopy[i];
                    scoresCopy[i] = scoresCopy[x];
                    scoresCopy[x] = holder;  

                    holder = iDCopy[i];
                    iDCopy[i] = iDCopy[x];
                    iDCopy[x] = holder;
               }
            }
        }
        System.out.println(Arrays.toString(iDCopy));
        System.out.println(Arrays.toString(scoresCopy));            
    }       
}

希望这可以解决您的问题。

如何关联java中的数组索引

2 个答案: