如何關聯java中的數組索引

Question

我在關聯兩個數組的索引時遇到了一個小問題，我似乎無法弄清楚。例如，我有一個

ID數組{365，222，306，203，113，208213}

和

比分數組{265,262,257,256,253,246,246}

它們完全匹配：ID [0 ]與分數[0]匹配，

任務：將21對數字（分別爲ID號和分數）讀取到兩個單獨的數組中。寫出配對的數字並按列標題由高到低排列。

到目前爲止，我已經能夠以降序成功打印分數，但是無法將它們與正確的ID號碼成功關聯。

任何幫助表示讚賞。

這是到目前爲止我的代碼：

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

當你做對的排序，只是做給iD陣列相同的變化：

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

順便說一下，用兩個單獨的數組是FORTRAN做事的方式。在現代編程語言中，您可以將兩個數字分組到一個結構/記錄/類中，然後僅使用一個具有此類的數組作爲元素。

Answer 2

您應該交換iDCopy索引，同時交換分數索引複製。

進行此更改你的代碼

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; 
     } 
    } 
} 

新的代碼看起來應該是這樣

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));    
    }  
} 

希望這會解決您的問題。