Java 示例 - 数组排序和插入

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  问题描述

  如何对数组进行排序并在其中插入元素？
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  解决方案

  下面的例子展示了如何使用 sort() 方法和用户定义的方法 insertElement() 来完成任务。

  
  import java.util.Arrays;
  public class MainClass {
     public static void main(String args[]) throws Exception {
        int array[] = { 2, 5, -2, 6, -3, 8, 0, -7, -9, 4 };
        Arrays.sort(array);
        printArray("Sorted array", array);
        
        int index = Arrays.binarySearch(array, 1);
        System.out.println("Didn't find 1 @ " + index);
        
        int newIndex = -index - 1;
        array = insertElement(array, 1, newIndex);
        printArray("With 1 added", array);
     }
     private static void printArray(String message, int array[]) {
        System.out.println(message + ": [length: " + array.length + "]");
        for (int i = 0; i < array.length; i++) {
           if (i != 0){
              System.out.print(", ");
           }
           System.out.print(array[i]);         
        }
        System.out.println();
     }
     private static int[] insertElement(int original[], int element, int index) {
        int length = original.length;
        int destination[] = new int[length + 1];
        System.arraycopy(original, 0, destination, 0, index);
        destination[index] = element;
        System.arraycopy(original, index, destination, index + 1, length - index);
        return destination;
     }
  }
  

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  结果

  上面的代码示例将产生以下结果。

  
  Sorted array: [length: 10]
  -9, -7, -3, -2, 0, 2, 4, 5, 6, 8
  Didn't find 1 @ -6
  With 1 added: [length: 11]
  -9, -7, -3, -2, 0, 1, 2, 4, 5, 6, 8
  

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