#include<iostream>
#include<stack>

using namespace std;
struct BinaryTreeNode
{
	int                 m_dbValue;
	BinaryTreeNode*        m_pLeft;
	BinaryTreeNode*        m_pRight;
};
//创建树节点
BinaryTreeNode* CreateBinaryTreeNode(int dbValue)
{
	BinaryTreeNode* pNode = new BinaryTreeNode();
	pNode->m_dbValue = dbValue;
	pNode->m_pLeft = nullptr;
	pNode->m_pRight = nullptr;

	return pNode;
}
//连接结点
void ConnectTreeNodes(BinaryTreeNode* pParent, BinaryTreeNode* pLeft, BinaryTreeNode* pRight)
{
	if (pParent != nullptr)
	{
		pParent->m_pLeft = pLeft;
		pParent->m_pRight = pRight;
	}
}
//释放内存
void DestroyTree(BinaryTreeNode* pRoot)
{
	if (pRoot != nullptr)
	{
		BinaryTreeNode* pLeft = pRoot->m_pLeft;
		BinaryTreeNode* pRight = pRoot->m_pRight;

		delete pRoot;
		pRoot = nullptr;

		DestroyTree(pLeft);
		DestroyTree(pRight);
	}
}
//分行从上到下"之"字形打印二叉树
void Print(BinaryTreeNode* pRoot)
{
	if (pRoot == nullptr)
		return;
//创建两个栈，一个保存当前的打印元素，一个保存下一行打印的元素
	std::stack<BinaryTreeNode*> stackTreeNode[2];
	int current = 0;
	int next = 1;
	stackTreeNode[current].push(pRoot);
	while (!stackTreeNode[current].empty() || !stackTreeNode[next].empty())
	{
		BinaryTreeNode* pNode = stackTreeNode[current].top();
		stackTreeNode[current].pop();
		printf("%d  ",pNode->m_dbValue);
//当奇数行时，先压入左子树到下一个栈，再压入右子树，偶数行则相反
		if (current == 0)
		{
			if (pNode->m_pLeft != nullptr)
				stackTreeNode[next].push(pNode->m_pLeft);
			if (pNode->m_pRight != nullptr)
				stackTreeNode[next].push(pNode->m_pRight);
		}
		else
		{
			if (pNode->m_pRight != nullptr)
				stackTreeNode[next].push(pNode->m_pRight);
			if (pNode->m_pLeft != nullptr)
				stackTreeNode[next].push(pNode->m_pLeft);
		}
//当当前行打印完，打印换行符，同时将当前栈换成下一个栈继续打印
		if (stackTreeNode[current].empty())
		{
			printf("\n");
			current = 1 - current;
			next = 1 - next;
		}
	}
}

int main()
{
	BinaryTreeNode* pNode10 = CreateBinaryTreeNode(10);
	BinaryTreeNode* pNode6 = CreateBinaryTreeNode(6);
	BinaryTreeNode* pNode14 = CreateBinaryTreeNode(14);
	BinaryTreeNode* pNode4 = CreateBinaryTreeNode(4);
	BinaryTreeNode* pNode8 = CreateBinaryTreeNode(8);
	BinaryTreeNode* pNode12 = CreateBinaryTreeNode(12);
	BinaryTreeNode* pNode16 = CreateBinaryTreeNode(16);

	ConnectTreeNodes(pNode10, pNode6, pNode14);
	ConnectTreeNodes(pNode6, pNode4, pNode8);
	ConnectTreeNodes(pNode14, pNode12, pNode16);

	Print(pNode10);

	DestroyTree(pNode10);

	return 0;
}