分治测试（快速排序） 

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <time.h>
 4 
 5 #define SIZE_ARRAY 100
 6 void quick_sort(int *array, int len); //分治
 7 
 8 
 9 int main()
10 {
11     int array[SIZE_ARRAY] = {0};
12     int i = 0, j = SIZE_ARRAY - 1;
13     int boop = 0;
14     srand((unsigned)time(NULL));
15     while(i < SIZE_ARRAY)
16     {
17         array[i] = rand() % SIZE_ARRAY;
18         i++;
19     }
20 
21     i = 0;
22     quick_sort(array, SIZE_ARRAY); //排序还有意思吗？
23 
24     while(i < j)
25     {
26         if(array[i] + array[j] == SIZE_ARRAY)
27         {
28             printf("I got it!\narray[%d] = %d, array[%d] = %d\n", i, array[i], j, array[j]);
29             boop = 1;
30             break;
31         }
32         else if(array[i] + array[j] > SIZE_ARRAY)
33         {
34             j--;
35         }
36         else
37         {
38             i++;
39         }
40     }
41 
42     if(0 == boop)
43     {
44         printf("I can't find it!\n");
45     }
46 
47     getchar();
48     return 0;
49 }
50 
51 
52 
53 
54 void quick_sort(int *array, int len) //分治
55 { 
56     int i = 0, j = len - 1;
57     int temp = array[i];
58 
59     if(len > 1)
60     {
61         while(i < j)
62         {
63             for(; j > i; j--)
64             {
65                 if(array[j] < temp)
66                 {
67                     array[i] = array[j];
68                     i++;
69                     break;
70                 }
71             }
72             for(; i < j; i++)
73             {
74                 if(array[i] > temp)
75                 {
76                     array[j] = array[i];
77                     j--;
78                     break;
79                 }
80             }
81         }
82 
83         array[i] = temp;
84         quick_sort(array, i);
85         quick_sort(array + i + 1, len - 1 - i);
86     }
87 
88 }

 

Python版本的快速排序，更容易读，更清晰

def quicksort(array):
    less = []; greater = []    
    if len(array) <= 1:
        return array
    pivot = array.pop()
    for x in array:    
        if x <= pivot:
            less.append(x)
        else:
           greater.append(x)
    return quicksort(less) + [pivot] + quicksort(greater)

 

R语言版本的快速排序

 

 

qs <- function(array){
if(length(array) <= 1){
    return (array)
}
 pivot = array[1]
 thers = array[-1]
 less = thers[thers < pivot]
 more = thers[thers >= pivot]
 qs(less)
 qs(more)
 return (c(less, pivot, more))
 }

 

 

 

 

 

posted @ 2014-04-21 09:26  kongmeng  阅读(201)  评论(0)  编辑  收藏  举报