c语言快速排序的实现

 1 //
 2 //  main.c
 3 //  cTest
 4 //
 5 //  Created by  on 13-10-8.
 6 //  Copyright (c) 2013年. All rights reserved.
 7 //
 8 
 9 #include <stdio.h>
10 
11 #define N (10)
12 
13 void quickSor(int *nums, int indexStart, int indexEnd);
14 int  partition(int *nums, int indexStart, int indexEnd);
15 void exchange(int *nums, int p1, int p2);
16 void printNums(int *nums, int count);
17 
18 int main()
19 {
20     printf(">>>strat\n");
21     int nums[N] = {0, 4, 2, 5, 1, 3, -1, 19, 99, -100};
22     printNums(nums, N);
23     int mid = partition(nums, 0, N-1);
24     printNums(nums, N);
25     printf("mid = %d\n", mid);
26     quickSor(nums, 0, N-1);
27     printNums(nums, N);
28     return 0;
29 }
30 
31 void quickSor(int *nums, int indexStart, int indexEnd)
32 {
33     if (indexEnd > indexStart)
34     {
35         int indexMid = partition(nums, indexStart, indexEnd);
36         quickSor(nums, indexStart, indexMid-1);
37         quickSor(nums, indexMid+1, indexEnd);
38     }
39     
40 }
41 
42 int partition(int *nums, int indexStart, int indexEnd)
43 {
44     
45     int p2 = indexStart-1;
46     int p1;
47     
48     int target = nums[indexEnd];
49     
50     for (p1 = indexStart; p1 < indexEnd; p1++)
51     {
52         if (nums[p1] <= target)
53         {
54             p2++;
55             exchange(nums, p1, p2);
56             
57         }
58     }
59     exchange(nums, p2+1, indexEnd);
60     return p2+1;
61 }
62 
63 void exchange(int *nums, int p1, int p2)
64 {
65     int tmp = nums[p1];
66     nums[p1] = nums[p2];
67     nums[p2] = tmp;
68 }
69 
70 void printNums(int *nums, int count)
71 {
72     printf("numbers : ");
73     int i;
74     for (i = 0; i < count; ++i)
75     {
76         printf("%4d\t", nums[i]);
77     }
78     printf("\n");
79 }