经典排序之快排数组模拟快排

 1 #include <stdio.h>
 2 
 3 int partition(int *a,int low ,int high)
 4 {
 5     int privotpos;
 6     int tem = a[low];
 7     privotpos = a[low];
 8     while(low<high)
 9     {
10         while(low<high && a[high]>=privotpos)high--;
11         a[low] = a[high];
12         while(low<high && a[low]<=privotpos)low++;
13         a[high] = a[low];
14     }
15     a[low] = tem;
16     return low;
17 }
18 
19 void sort(int *a,int low,int high)
20 {
21     int privotpos;
22     if(low<high)
23     {
24         privotpos = partition(a,low,high);
25         sort(a,low,privotpos-1);
26         sort(a,privotpos+1,high);
27     }
28 }
29 
30 int main()
31 {
32     int i,*p;
33     int length;
34     int a[12];
35 //    length = a.length();
36     length = 10;
37     printf("Enter 10 numbers:\n");
38     for(i = 0; i < length; i++)
39 //    scanf("%d",(a+i));
40     scanf("%d",&a[i]);
41 
42     printf("Before ordered:\n");
43     for(i = 0; i < length; i++)
44     printf("%d ",*(a+i));
45     printf("\n\n");
46 //  quick sort
47 //    p = a;
48     sort(a,0,length-1);
49 
50     printf("After ordered:\n");
51     for(i = 0; i < length; i++)
52     printf("%d ",*(a+i));
53     printf("\n");
54     return 0;
55 }

快排原理，每次找一个标志位，然后遍历数组，大于该位的放在其前边，小于该位的放于其后边，然后在对两侧的小数组进行便如此计算，知道排好序为止。代码如上。