图解快数排序法

Posted 2020-10-23 linbobo

快速排序图解：

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java 代码的实现：

 1 package main.test;
 2 
 3 public class KSSort {
 4     public static int Partition(int[] a, int p, int r) {
 5         int x = a[r - 1];
 6         int i = p - 1;
 7         int temp;
 8         for (int j = p; j <= r - 1; j++) {
 9             if (a[j - 1] <= x) {
10 // 交换(a[j-1],a[i-1]);
11                 i++;
12                 temp = a[j - 1];
13                 a[j - 1] = a[i - 1];
14                 a[i - 1] = temp;
15             }
16         }
17 //交换(a[r-1,a[i+1-1]);
18         temp = a[r - 1];
19         a[r - 1] = a[i + 1 - 1];
20         a[i + 1 - 1] = temp;
21         return i + 1;
22     }
23 
24 
25     public static void QuickSort(int[] a,int p,int r){
26         if(p<r){
27             int q=Partition(a,p,r);
28             QuickSort(a,p,q-1);
29             QuickSort(a,q+1,r);
30         }
31     }
32 
33     static void print(int[] a) {
34         for (int values : a
35                 ) {
36             System.out.print(values+" | ");
37         }
38     }
39 
40 
41     public static void main(String[] args) {
42         int[] a={7,10,3,5,4,6,2,8,1,9};
43         QuickSort(a,1,10);
44         print(a);
45 
46 
47     }
48 
49 
50 }

View Code

 

 1 public class QuickSort {
 2     public static void quickSort(int[] arr,int low,int high){
 3         int i,j,temp,t;
 4         if(low>high){
 5             return;
 6         }
 7         i=low;
 8         j=high;
 9         //temp就是基准位
10         temp = arr[low];
11 
12         while (i<j) {
13             //先看右边，依次往左递减
14             while (temp<=arr[j]&&i<j) {
15                 j--;
16             }
17             //再看左边，依次往右递增
18             while (temp>=arr[i]&&i<j) {
19                 i++;
20             }
21             //如果满足条件则交换
22             if (i<j) {
23                 t = arr[j];
24                 arr[j] = arr[i];
25                 arr[i] = t;
26             }
27 
28         }
29         //最后将基准为与i和j相等位置的数字交换
30          arr[low] = arr[i];
31          arr[i] = temp;
32         //递归调用左半数组
33         quickSort(arr, low, j-1);
34         //递归调用右半数组
35         quickSort(arr, j+1, high);
36     }
37 
38 
39     public static void main(String[] args){
40         int[] arr = {10,7,2,4,7,62,3,4,2,1,8,9,19};
41         quickSort(arr, 0, arr.length-1);
42         for (int i = 0; i < arr.length; i++) {
43             System.out.println(arr[i]);
44         }
45     }
46 }