快速排序

template<typename T>
void Sort(T arrayT[], int begin, int end)
{
	int low = begin;
	int high = end;

	int key = arrayT[low];
	while (low < high)
	{
		// 从后面找比key小的值
		while(arrayT[high] >= key && high > low)
			--high;

		if (high <= low)
			break;
		arrayT[low] = arrayT[high];

		while(arrayT[low] <= key && low < high)
			++low;

		if (high <= low)
			break;

		arrayT[high] = arrayT[low];
	}

	arrayT[low] = key;

	if (low <= high)
	{
		if (begin < low - 1)
			Sort(arrayT, begin, low - 1);

		if (end > high + 1)
			Sort(arrayT, high + 1, end);
	}
}

快速排序是稳定的