12.11学习总结

（1）今日安排

快速排序

题目要求：本题要求实现快速排序的一趟划分函数，待排序列的长度1<=n<=1000。

#include<stdio.h>
#include<stdlib.h>
typedef  int  KeyType;
typedef  struct {                      
  KeyType *elem; /*elem[0]一般作哨兵或缓冲区*/                       
  int Length;      
}SqList;
void  CreatSqList(SqList *L);/*待排序列建立，由裁判实现，细节不表*/ 
int Partition ( SqList  L,int low,  int  high );
void Qsort ( SqList  L,int low,  int  high );
int main()
{
  SqList L;
  int i;
  CreatSqList(&L);
  Qsort(L,1,L.Length);
  for(i=1;i<=L.Length;i++)
   {        
     printf("%d ",L.elem[i]);
   }
  return 0;
}
void Qsort ( SqList  L,int low,  int  high ) 
{  int  pivotloc;
   if(low<high)
    {  
    pivotloc = Partition(L, low, high ) ;
        Qsort (L, low, pivotloc-1) ; 
        Qsort (L, pivotloc+1, high );
     }
}
int Partition ( SqList  L,int low,  int  high ){
    L.elem[0]=L.elem[low];
    int l=low,r=high;
    while(l<r){
        while(r>l&&L.elem[r]>=L.elem[0]) r--;
        L.elem[l]=L.elem[r];
        while(l<r&&L.elem[l]<=L.elem[0]) l++;
        L.elem[r]=L.elem[l];
    }
    L.elem[l]=L.elem[0];
    return l;
}