快速排序,void Qsort(void *base,int nelem,int width, int (*fcmp)(const void *,const void *))的实现。

void swap(void * pLeft, void * pRight , int width)
{
    void * tmp = malloc(width);
    memcpy( tmp , pLeft , width );
    memcpy( pLeft , pRight , width );
    memcpy( pRight, tmp , width );
    free(tmp);
    tmp = NULL;
}

void qs( void *pHead ,int begin, int end , int width, int (*fcmp)(const void *,const void *))
{
    void * compare = malloc(width);
    memcpy( compare , &((char *)pHead)[begin*width], width);
    
    int left = begin;
    int right = end;
    
    if (left > right) {
        return;
    }
    while (left < right) {
        while ( (left < right) && (fcmp( &((char *)pHead)[right*width] , compare )) >= 0 ) {
            right--;
        }
        swap( &((char *)pHead)[left*width], &((char *)pHead)[right*width], width);
        
        while ( (left < right) && (fcmp( &((char *)pHead)[left*width] , compare )) < 0 ) {
            left++;
        }
        swap(&((char *)pHead)[right*width], &((char *)pHead)[left*width], width );
    }
    memcpy( &((char *)pHead)[right*width] , &((char *)pHead)[left*width], width);
    qs( pHead , begin , right - 1 , width , fcmp);
    qs( pHead , right + 1 , end , width , fcmp);
    
    free(compare);
    compare = NULL;
}

void mryQsort(void *base,int nelem,int width, int (*fcmp)(const void *,const void *))
{
    qs( base , 0, nelem - 1 , width , fcmp);
}

int cmp (const void * a,const void * b)
{
    return  -(*(int*)a - *(int*)b);
}
int main(int argc, char *argv[])
{
    int a[9] = {4,2,3,1,6,5,7,9,8};
    ccBsort( a, 10, 4, funp);
    mryQsort( a , 9, 4, funp);
}

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