快速排序

#include <stdio.h>

#define CUTOFF 3

typedef int ElementType;

void SwapTwoNum(ElementType *Num_1,ElementType *Num_2)
{
    int NumTemp = *Num_1;
    *Num_1 = *Num_2;
    *Num_2 = NumTemp;
}

// Return Median of left,center,and right
//order these and hide the pivot
ElementType Median3(ElementType *Array,int Left,int Right)
{
    int Center = (Left + Right) / 2;
    
    // C >= L,R >= L,R >= C ---> L <= C <= R
    if(Array[Left] > Array[Center])
    {
        SwapTwoNum(&Array[Left],&Array[Center]);
    }
    if(Array[Left] > Array[Right])
    {
        SwapTwoNum(&Array[Left],&Array[Right]);
    }
    if(Array[Center] > Array[Right])
    {
        SwapTwoNum(&Array[Center],&Array[Right]);
    }
    
    //Hide pivot
    SwapTwoNum(&Array[Center],&Array[Right-1]);
    return Array[Right-1];
}

void InsertionSort(ElementType *Array,int ArrayLen)
{
    int i,j;
    ElementType ExtractElem;
    for(i = 1;i < ArrayLen;i ++)
    {
        ExtractElem = Array[i];
        for(j = i;j > 0 && ExtractElem < Array[j-1];j --)
        {
            Array[j] = Array[j-1];
        }
        //Insert
        Array[j] = ExtractElem;
    }
}

void QSort(ElementType *Array,int Left,int Right)
{
    int i,j;
    ElementType Pivot;
    
    if(Left + CUTOFF <= Right)
    {
        Pivot = Median3(Array,Left,Right);
        i = Left;j = Right - 1;
        while(1)
        {
            while(Array[++i] < Pivot)
                ;
            while(Array[--j] > Pivot)
                ;
            if(i < j)
            {
                SwapTwoNum(&Array[i],&Array[j]);
            }
            else
            {
                break;
            }
        }
        
        //restore pivot
        SwapTwoNum(&Array[i],&Array[Right-1]);
        
        QSort(Array,Left,i-1);
        QSort(Array,i+1,Right);
    }
    else
    {
        InsertionSort(Array+Left,Right-Left+1);
    }
}

void QuickSort(ElementType *Array,int ArrayLen)
{
    QSort(Array,0,ArrayLen-1);
}

int main()
{
    ElementType TestArray[10] = {718,224,3332,4443,55,31,66,79,90,7};
    QuickSort(TestArray,10);
    int i;
    for(i = 0;i < 10;i ++)
    {
        printf("%d ",TestArray[i]);
    }
    printf("
");
    return 0;
}