Java實現快速排序算法

 1 package xiaoling;  2 public class QuickSort{  3         public static void main(String[] args){  4                 int[] nums = new int[20];  5                 for (int loc = 0; loc < nums.length; ++loc){  6                         nums[loc] = (int) (Math.random() * 100) + 5;  7  }  8                 for (int num: nums) System.out.print(num + " ");  9                 System.out.println("\n-----------------------"); 10                 QS(nums, 0, nums.length-1); 11                 for (int num: nums) System.out.print(num + " "); 12  System.out.println(); 13  } 14         public static  void QS(int[] nums, int low, int high){ 15                 if (low >= high) return; 16                 int mid = getMiddle(nums, low, high); 17                 QS(nums, mid+1, high); 18                 QS(nums, 0, mid-1); 19  } 20         public static int getMiddle(int[] nums, int low, int high){ 21                 int temp = nums[low]; 22                 while (low < high){ 23                         while (low < high && nums[high] >= temp) --high; 24                         nums[low] = nums[high]; 25                         while (low < high && nums[low] <= temp) ++low; 26                         nums[high] = nums[low]; 27  } 28                 nums[low] = temp; 29                 return low; 30  } 31 }

運行結果：