快速排序c

1 #include <stdio.h>
      2 #include <stdlib.h>
      3 #include <unistd.h>
      4
      5 int a[10] =  {49,38,65,97,76,13,27,22,15,87};
      6
      7 void qs(begin,end){
      8     int key = a[begin],l_hold = begin,r_hold = end;
      9     while(begin<end){
     10         //first from right,find one that < key
     11         while(begin < end && a[end] >= key){
     12             end--;
     13         }
     14         //if they do not point to the same
     15         if(begin != end){
     16             a[begin++] = a[end];
     17         }
     18
     19         //the next step we from left,find one that > key
     20         while(begin < end && a[begin] <= key){
     21             begin++;
     22         }
     23         //if they do not point to the same
     24         if(begin != end){
     25             a[end--] = a[begin];
     26         }
     27     }
     28     //we get begin == end now,put the key in this place
     29     a[begin] = key;
     30     //now position to middle
     31     int middle = begin;
     32     //1rst sort over,a is splited into [section1(l_hold,P-1),(P+1,r_hold)seciont2()]
     33     //for left
     34
     35     int i = 0;
     36     for(;i<10;i++){
     37         printf("\t%d",a[i]);
     38     }
     39         printf("\n");
     40
     41     if(l_hold < middle)
     42         qs(l_hold,middle-1);
     43     //for right
     44     if(r_hold > middle)
     45         qs(middle+1,r_hold);
     46 }
     47
     48 int
     49 main(){
     50     int i = 0;
     51     for(;i<10;i++){
     52         printf("\t%d",a[i]);
     53     }
     54         printf("\n");
     55
     56     qs(0,9);
     57 }

==end