快速排序的Java實現

 1 package quicksort;
 2 
 3 import org.junit.Test;
 4 
 5 import java.util.Arrays;
 6 
 7 public class QuickSort {
 8 
 9     @Test
10     public void setUp() throws Exception {
11         int[] arr = new int[]{32, 26, 83, 55, 42, 67, 73, 92, 60};
12         quickSort(arr, 0, arr.length - 1);
13         System.out.println(Arrays.toString(arr));
14     }
15 
16     public void quickSort(int[] arr, int low, int high) {
17         if (low < high) {
18             int temp = quickPartition(arr, low, high);
19             quickSort(arr, low, temp - 1);
20             quickSort(arr, temp + 1, high);
21         }
22     }
23 
24     public int quickPartition(int[] arr, int low, int high) {
25         int key = arr[low];
26         while (low < high) {
27             while (low < high && arr[high] >= key) {
28                 high--;
29             }
30             arr[low] = arr[high];
31             while (low < high && arr[low] <= key) {
32                 low++;
33             }
34             arr[high] = arr[low];
35         }
36         arr[low] = key;
37         return low;
38     }
39 }