在Java中切換對象數組中的最小和最大值

Question

我被要求交換Java對象數組中的最大和最小值。 我寫了我的代碼，這似乎很合理，但是由於某些原因，這些值沒有切換？？？ 我不太確定自己的代碼有什么問題，有人可以向我指出正確的方向嗎？ 謝謝！！

這是我的代碼：

public class Measurables
{
   /**
      Swaps the values with the smallest and largest measure.
      @param objects an array of objects of a class that implements the
      Measurable interface.
   */
   public static void swapMinAndMax(Measurable[] objects)
   {

      Measurable largest = objects[0]; 
      Measurable smallest = largest;
      for (int i = 1 ; i < objects.length ; i++)
      {
         Measurable current = objects[i];
         if ( largest.getMeasure() < current.getMeasure())
         {
            largest = current;
         }
         if (smallest.getMeasure() < current.getMeasure())
         {
            smallest = current;
         }
         Measurable temp = largest; 
         largest = smallest;
         smallest = temp;

         }
      }
}

這是我運行測試儀時得到的：

Testers

Running Tester.java

fail
[Uruguay, Thailand, Belgium]
Expected: [Uruguay, Belgium, Thailand]
Running Tester2.java

fail
[BankAccount[balance=1000.0], BankAccount[balance=3000.0], BankAccount[balance=2000.0]]
Expected: [BankAccount[balance=3000.0], BankAccount[balance=1000.0], BankAccount[balance=2000.0]]
Running Tester3.java

pass
[Uruguay]
Expected: [Uruguay]

Answer 1

您應該存儲元素的索引，以便在確定最小和最大索引后可以執行交換。 另外，您似乎已將比較換成最小的。 就像是，

public static void swapMinAndMax(Measurable[] objects) {
    int largest = 0, smallest = 0;
    for (int i = 1; i < objects.length; i++) {
        Measurable current = objects[i];
        if (objects[largest].getMeasure() < current.getMeasure()) {
            largest = i;
        }
        if (objects[smallest].getMeasure() > current.getMeasure()) {
            smallest = i;
        }
    }
    // Now swap, we know the indexes.
    Measurable temp = objects[largest];
    objects[largest] = objects[smallest];
    objects[smallest] = temp;
}