快速排序

#include <stdio.h>

//this program is edited by 200624101101楊振平

//this paper's edited time is Nov 7th,2008

//define count of array

#define N 9

//main function

void main()

{

 //declare QuickSort function

 void QuickSort(int r[ ], int first, int end);

 //initial the array r[] which require to sort

 int r[N]={9,8,7,6,5,4,3,2,1};

 //call the QuickSort function

 QuickSort(r,0,N-1);

 //print the sort result array

 for(int i=0;i<N;i++)

  printf("%d/t",r[i]);

}

//implement the QuickSort function

void QuickSort(int r[ ], int first, int end)

 //declare Partition function

 int Partition(int r[ ], int first, int end);

 //declare variable which axis value location in the array

 int pivot;

    if (first<end) {

  //problem divide conquer,pivot to store axis value location in the array

        pivot=Partition(r, first, end); 

        //recurrence to left son array to do quick sort

        QuickSort(r, first, pivot-1);

        //recurrence to right son array to do quick sort

        QuickSort(r, pivot+1, end);

    }

//implement the Partition function

int Partition(int r[ ], int first, int end)

 //declare and init variables

    int i=first;

 int j=end;

 int temp;

 //exchange records to partition the array

    while (i<j)

    {

    //right scan

       while (i<j && r[i]<= r[j]) j--;

               if (i<j) {

     //exchange the min record to the front

                 temp=r[j];

     r[j]=r[i];

     r[i]=temp;

                 i++;

       }

    //left scan

       while (i<j && r[i]<= r[j]) i++;

       if (i<j) {

     //exchange the man record to the last

     temp=r[j];

     r[i]=temp;         

                 j--;

 //i is the last axis value location in the array

    return i;