排序

//堆排序
static void  swap(int &a,int &b)
{
	if (a!=b)
	{
		a=a^b;
		b=a^b;
		a=a^b;
	}
}
void siftdown(int array[],int i, int length)
{
	int j;
	for (j = 2*i+1; j < length ;)
	{
		if (j+1<length && array[j]<array[j+1])
		{
			j++;
		}
		if (array[j]>array[i])
		{
			swap(array[j],array[i]);
		}
		i=j;
		j=2*i+1;

	}
}

void HeapSort(int array[],int length)
{
	if (NULL == array || length <=0)
	{
		return ;
	}
	int i;
	for ( i = (length>>1)-1; i >=0;--i )
	{
		siftdown(array,i,length);
	}
	for (i=length-1;i>0;--i)
	{
		swap(array[0],array[i]);
		siftdown(array,0,i);
	}


}

//归并排序
void merge(int array[],int low, int mid,int high)
{
	int i,j,k;
	int *temp = new int[high-low+1];
	
	assert(temp);
	i=low,j=mid+1,k=0;
	while (i<=mid&&j<=high)
	{
		if (array[i]<array[j])
		{
			temp[k++]=array[i++];
		}
		else
			temp[k++]=array[j++];
	}

	while (i<=mid)
	{
		temp[k++]=array[i++];
	}
	while (j<=high)
	{
		temp[k++]=array[j++];
	}
	for (i=low,j=0;i<=high;++i)
	{
		array[i]=temp[j++];
	}
	delete []temp;
}
void MergeSort(int array[],int low, int high)
{
	int mid;
	if (low < high)
	{
		mid = (low+high)>>1;
		MergeSort(array,low,mid);
		MergeSort(array,mid+1,high);
		merge(array,low,mid,high);
	}
}