归并排序

#include <stdio.h>
#include <malloc.h>

typedef int ElementType;

void _Merge(ElementType *Array,ElementType *TmpArray,int LeftStart,int RightStart,int RightEnd)
{
    int i;
    int ArrayLen = RightEnd - LeftStart + 1;
    int LeftEnd = RightStart - 1;
    int TmpArrayEnd = LeftStart;
    
    while(LeftStart <= LeftEnd && RightStart <= RightEnd)
    {
        if(Array[LeftStart] <= Array[RightStart])
        {
            TmpArray[TmpArrayEnd++] = Array[LeftStart++];
        }
        else
        {
            TmpArray[TmpArrayEnd++] = Array[RightStart++];
        }
    }
    
    while(LeftStart <= LeftEnd)
    {
        TmpArray[TmpArrayEnd++] = Array[LeftStart++];
    }
    while(RightStart <= RightEnd)
    {
        TmpArray[TmpArrayEnd++] = Array[RightStart++];
    }
    
    //copy TmpArray back to Array
    for(i = 0;i < ArrayLen;i ++,RightEnd --)
    {
        Array[RightEnd] = TmpArray[RightEnd];
    }
}

void _MSort(ElementType *Array,ElementType *TmpArray,int Left,int Right)
{
    int Center;
    
    if(Left < Right)
    {
        Center = (Left + Right) / 2;
        _MSort(Array,TmpArray,Left,Center);
        _MSort(Array,TmpArray,Center+1,Right);
        _Merge(Array,TmpArray,Left,Center+1,Right);
    }
}

void MergeSort(ElementType *Array,int ArrayLen)
{
    ElementType *TmpArray;
    
    TmpArray = malloc(ArrayLen * sizeof(ElementType));
    
    _MSort(Array,TmpArray,0,ArrayLen-1);
    free(TmpArray);
}

int main()
{
    ElementType TestArray[10] = {9,2,4,1,2,5,9,3,7};
    MergeSort(TestArray,10);
    int i;
    for(i = 0;i < 10;i ++)
    {
        printf("%d ",TestArray[i]);
    }
    printf("\n");
    return 0;
}