C语言算法--插入排序

/*-----------------------------
*
* For    排序算法学习
* IDE    DEV-CPP4.9.2
* Auhtor  Czp
* Date   2012/10/17
*------------------------------
*/
#include <stdlib.h>
#include <stdio.h>
//插入排序
void insertSort(int* arr,size_t n)      
{
     
      int i,j,key;
      for(i=1;i<n;i++)                      //初始:ar={169,45,2,489,469,4,-778,156}
      {                                    
          key = arr[i];                 
          j=i-1;
          while(j>=0&&arr[j]>key)          //把key与前面的arr[0~j]进行比较  
                  arr[j+1] = arr[j--];     //找到一个比key大的数就把它后移 
          arr[j+1]=key;                    //上面的循环终止，则j+1就key的位置  
      }  
      /*
      *Loop0:169,45,2,489,469,4,-778,156  数组原型  取key=arr[2]=2 
      *Loop1:2,169,45,489,469,4,-778,156  key=2比arr[1] arr[0]小，找到arr[2]的位置arr[0]->
      *Lopp3:2,169,45,469,489,4,-778,156  进行插入和ArrayList的insert(value,index)一样 
      *Loop4:2,169,45,469,489,4,-778,156  .......
      *Loop5:2,4,169,45,469,489,-778,156  ...
      *Loop6:-778,2,4,169,45,469,489,156  ...
      *Loop7:-778,2,4,156,169,45,469,489  ...
      */
} 

 int main(int argc, char *argv[])
 {
     int arr[] = {169,45,2,489,469,4,-778,156};
     size_t len = (sizeof arr/sizeof arr[0]);
     insertSort(arr,len);
     int i;
     for(i=0;i<len;i++)
     {
         printf("%d ,",arr[i]);               
     }
     //====>-778,2,4,156,169,45,469,489
     getchar();
     return 0;
 }