二叉树代码(较全)

#include <iostream>
#include <vector>
#include <list>
using namespace std;

// 节点结构体
typedef struct node
{
	int 	data;
	node*	leftChild;
	node*	rightChild;
	bool	leftVisited;
	bool	rightVisited;

	node()
	{
		int data		= -1;
		leftChild		= NULL;
		rightChild		= NULL;
		leftVisited		= false;
		rightVisited	= false;
	}

}Node, *pNode;

//******************************************************************************
// Name: CreateChild
// Desc: 创建子树
//******************************************************************************
void CreateChild(Node* &root, vector<int>::iterator &beginIter, 
				 vector<int>::iterator &endIter)
{
	if(beginIter != endIter)
	{
		int tempData = *beginIter++;
		if(tempData != -1)
		{
			root = new Node;
			root->data = tempData;
			CreateChild(root->leftChild, beginIter, endIter);	// 创建左子树
			CreateChild(root->rightChild, beginIter, endIter);	// 创建右子树
		}
		else
		{
			root = NULL;
		}
	}
	else
	{
		root = NULL;
	}
}

//******************************************************************************
// Name: CreateTree
// Desc: 先序扩展序列创建一棵树（先序遍历，空节点用-1标识）
//******************************************************************************
Node* CreateTree(Node* root, vector<int> &dataVec)
{
	if(dataVec.size() < 1)	return NULL;
	
	vector<int>::iterator beginIter = dataVec.begin();
	vector<int>::iterator endIter	= dataVec.end();

	root = NULL;
	CreateChild(root, beginIter, endIter);
	
	return root;
}

//******************************************************************************
// Name: DisplayTree
// Desc: 二叉显示
//******************************************************************************
void DisplayTree(Node* root)
{
	if(root != NULL)
	{
		cout<<"node:"<<root->data<<" ";
		if(root->leftChild != NULL)
		{
			cout<<"leftChild:"<<root->leftChild->data<<" ";
		}
		if(root->rightChild != NULL)
		{
			cout<<"rightChild:"<<root->rightChild->data<<" ";
		}
		cout<<endl;

		DisplayTree(root->leftChild);
		DisplayTree(root->rightChild);
	}
}

//******************************************************************************
// Name: FirstVisite
// Desc: 先根遍历(递归)
//******************************************************************************
void FirstVisite(Node* root)
{
	if(root != NULL)
	{
		cout<<root->data<<" ";
		FirstVisite(root->leftChild);
		FirstVisite(root->rightChild);
	}
}

//******************************************************************************
// Name: CenterVisite
// Desc: 中根遍历(递归)
//******************************************************************************
void CenterVisite(Node* root)
{
	if(root != NULL)
	{
		CenterVisite(root->leftChild);
		cout<<root->data<<" ";
		CenterVisite(root->rightChild);
	}
}

//******************************************************************************
// Name: AfterVisite
// Desc: 后根遍历(递归)
//******************************************************************************
void AfterVisite(Node* root)
{
	if(root != NULL)
	{
		AfterVisite(root->leftChild);
		AfterVisite(root->rightChild);
		cout<<root->data<<" ";
	}
}

//******************************************************************************
// Name: ResetTree
// Desc: 重置二叉树，方便一次遍历
//******************************************************************************
void ResetTree(Node* root)
{
	if(root != NULL)
	{
		root->leftVisited	= false;
		root->rightVisited	= false;
		ResetTree(root->leftChild);
		ResetTree(root->rightChild);
	}
}

//******************************************************************************
// Name: _FirstVisite
// Desc: 先根遍历(非递归)
//******************************************************************************
void _FirstVisite(Node* tree)
{
	ResetTree(tree);

	typedef vector<Node*> NodeStack;
	NodeStack stack;
	stack.push_back(tree); // 初始化栈

	while (stack.size() > 0)
	{
		Node* topNode = stack.back();
		if (!topNode->leftVisited && !topNode->rightVisited)
		{
			cout<<topNode->data<<" ";
		}

		if (topNode->leftChild != NULL && !topNode->leftVisited)
		{
			stack.push_back(topNode->leftChild);
			topNode->leftVisited = true;
		}
		else if (topNode->rightChild != NULL && !topNode->rightVisited)
		{
			stack.push_back(topNode->rightChild);
			topNode->rightVisited = true;
		} 
		else
		{
			stack.pop_back();
		}
	}
}

//******************************************************************************
// Name: __FirstVisite
// Desc: 非递归先根遍历思路二
//******************************************************************************
void __FirstVisite(Node* tree)
{
	typedef vector<Node*> NodeStack;
	NodeStack stack;
	Node *curNode = tree;
	while(!stack.empty() || curNode != NULL)
	{
		while(curNode != NULL)
		{
			cout<<curNode->data<<" ";
			stack.push_back(curNode);
			curNode = curNode->leftChild;
		}

		if(!stack.empty())
		{
			curNode = stack.back();
			curNode = curNode->rightChild;
			stack.pop_back();
		}
	}
}

//******************************************************************************
// Name: _CenterVisit
// Desc: 中根遍历(非递归)
//******************************************************************************
void _CenterVisite(Node* tree)
{
	ResetTree(tree);

	typedef vector<Node*> NodeStack;
	NodeStack stack;
	stack.push_back(tree);	//  初始化

	while (stack.size() > 0)
	{
		Node* topNode = stack.back();
		if (topNode->leftVisited && !topNode->rightVisited)
		{
			cout<<topNode->data<<" ";
		}


		if (topNode->leftChild != NULL && !topNode->leftVisited)
		{
			stack.push_back(topNode->leftChild);
			topNode->leftVisited = true;
		}
		else 
		{
			if (topNode->rightChild != NULL && !topNode->rightVisited)
			{
				if (topNode->leftChild == NULL && topNode->rightChild != NULL)
				{
					cout<<topNode->data<<" ";		// 单边只有右子节点
				}
				stack.push_back(topNode->rightChild);
				topNode->rightVisited = true;
			} 
			else
			{
				if (topNode->leftChild == NULL && topNode->rightChild == NULL)
				{
					cout<<topNode->data<<" ";
				}
				stack.pop_back();
			}
		}
	}
}

//******************************************************************************
// Name: __CenterVisite
// Desc: 非递归中根遍历思路二
//******************************************************************************
void __CenterVisite(Node* tree)
{
	typedef vector<Node*> NodeStack;
	NodeStack stack;

	Node* curNode = tree;
	while(!stack.empty() || curNode != NULL)
	{
		while(curNode != NULL)
		{
			stack.push_back(curNode);
			curNode = curNode->leftChild;
		}

		if(!stack.empty())
		{
			curNode = stack.back();
			cout<<curNode->data<<" ";
			curNode = curNode->rightChild;
			stack.pop_back();
		}
	}
}

//******************************************************************************
// Name: _AfterVisite
// Desc: 后序遍历(非递归)
//******************************************************************************
void _AfterVisite(Node* tree)
{
	ResetTree(tree);

	typedef vector<Node*> NodeStack;
	NodeStack stack;
	stack.push_back(tree);				// 初始化

	while (stack.size())
	{
		Node* topNode = stack.back();
		if (topNode->leftVisited && topNode->rightVisited)
		{
			cout<<topNode->data<<" ";
		}

		if (topNode->leftChild != NULL && !topNode->leftVisited)
		{
			stack.push_back(topNode->leftChild);
			topNode->leftVisited = true;
		}
		else if (topNode->rightChild != NULL && !topNode->rightVisited)
		{
			stack.push_back(topNode->rightChild);
			topNode->rightVisited = true;
		}
		else
		{
			// 针对叶子节点或者单边子节点的情况
			if (topNode->leftChild == NULL || topNode->rightChild == NULL)
			{
				cout<<topNode->data<<" ";
			}
			stack.pop_back();
		}
	}
}


//******************************************************************************
// Name: __AfterVisite
// Desc: 非递归后根遍历思路二
//******************************************************************************
void __AfterVisite(Node* tree)
{
	typedef vector<Node*> StackNode;
	StackNode stack;

	Node *curNode;								// 当前结点 
	Node *preNode = NULL;						// 前一次访问的结点 
	stack.push_back(tree);

	while(!stack.empty())
	{
		curNode = stack.back();

		if((curNode->leftChild == NULL && curNode->rightChild == NULL) ||
			(preNode != NULL && (preNode == curNode->leftChild || preNode == curNode->rightChild)))
		{
			cout<<curNode->data<<" ";			// 如果当前结点没有孩子结点或者孩子节点都已被访问过 
			stack.pop_back();
			preNode = curNode; 
		}
		else
		{
			if(curNode->rightChild != NULL)
			{
				stack.push_back(curNode->rightChild);	
			}
			if(curNode->leftChild != NULL)
			{
				stack.push_back(curNode->leftChild);
			}
		}
	}    
}

//******************************************************************************
// Name: LevelVisite
// Desc: 层次遍历
//******************************************************************************
void LevelVisite(Node* tree)
{
	typedef list<Node*> QueueNode;
	QueueNode queue;
	queue.push_back(tree);

	while (queue.size() > 0)			//由上至下，由左至右
	{
		Node* curNode = queue.front();
		queue.pop_front();
		cout<<curNode->data<<" ";

		if (curNode->leftChild != NULL)
		{
			queue.push_back(curNode->leftChild);
		}
		if (curNode->rightChild != NULL)
		{
			queue.push_back(curNode->rightChild);
		}
	}
}

//******************************************************************************
// Name: CaculateLeafNum
// Desc: 统计叶子节点的数量
//******************************************************************************
int CaculateLeafNum(Node* tree)
{
	if (tree == NULL)
	{
		return 0;
	}

	if (tree->leftChild == NULL && tree->rightChild == NULL)	//孤立点
	{
		return 1;
	}

	//递归计算
	int sum = 0;
	sum += CaculateLeafNum(tree->leftChild);
	sum += CaculateLeafNum(tree->rightChild);

	return sum;
}

//******************************************************************************
// Name: CaculateAllNodeNum
// Desc: 统计所有节点数量
//******************************************************************************
int CaculateAllNodeNum(Node* tree)
{
	/*static int sum = 0;
	if(tree != NULL)
	{
		sum += 1;

		CaculateAllNodeNum(tree->leftChild);
		CaculateAllNodeNum(tree->rightChild);
	}*/

	int sum = 0;
	if (tree != NULL)
	{
		sum = 1;
		sum += CaculateAllNodeNum(tree->leftChild);
		sum += CaculateAllNodeNum(tree->rightChild);
	}

	return sum;	
}

//******************************************************************************
// Name: CaculateDepth
// Desc: 计算二叉树的深度
//******************************************************************************
int CaculateDepth(Node* tree)
{
	int leftDepth	= 0;
	int rightDepth	= 0;

	if(tree != NULL)
	{
		leftDepth = 1;
		leftDepth += CaculateDepth(tree->leftChild);

		rightDepth = 1;
		rightDepth += CaculateDepth(tree->rightChild);
	}

	return leftDepth > rightDepth ? leftDepth : rightDepth;
}

//******************************************************************************
// Name: CaculateWidth
// Desc: 计算二叉树的宽度
//******************************************************************************
int CaculateWidth(Node* tree)
{
	if (tree == NULL)
	{
		return 0;
	}

	typedef list<Node*> QueueNode;
	QueueNode queue;
	unsigned int width = 0;
	queue.push_back(tree);

	while (queue.size() > 0)
	{
		unsigned int size = queue.size();

		for (unsigned int i = 0; i < size; ++i)	// 上一层的节点全部出列,并压入下一层节点
		{
			Node* curNode = queue.front();
			queue.pop_front();

			if (curNode->leftChild != NULL)
			{
				queue.push_back(curNode->leftChild);
			}

			if (curNode->rightChild != NULL)
			{
				queue.push_back(curNode->rightChild);
			}
			
		}
		width = max(width, size);				// 与每一个size比较，取最大者
	}

	return width;
}

//******************************************************************************
// Name: Release
// Desc: 释放资源
//******************************************************************************
void Release(Node* tree)
{
	if(tree != NULL)
	{
		Release(tree->leftChild);
		Release(tree->rightChild);
		delete tree;
		tree = NULL;
	}
}


int main()

{
	// 数据输入
	vector<int> dataVec;
	int			tempValue;
	cout<<"请输入二叉树的先序扩展序列(-1为空):"<<endl;
	while(cin>>tempValue)
	{
		dataVec.push_back(tempValue);
	}

	// 二叉树的创建
	Node* root = NULL;
	root = CreateTree(root, dataVec);	

	// 二叉显示
	DisplayTree(root);

	// 递归先根遍历
	FirstVisite(root);
	cout<<endl;

	// 递归中根遍历
	CenterVisite(root);
	cout<<endl;

	// 递归后根遍历
	AfterVisite(root);
	cout<<endl;

	cout<<"----------------------------"<<endl;

	// 非递归先根遍历
	_FirstVisite(root);
	cout<<endl;

	// 非递归先根遍历二
	__FirstVisite(root);
	cout<<endl;

	// 非递归中根遍历
	_CenterVisite(root);
	cout<<endl;

	// 非递归中根遍历思路二
	__CenterVisite(root);
	cout<<endl;

	// 非递归后根遍历
	_AfterVisite(root);
	cout<<endl;

	// 非递归后根遍历思路二
	__AfterVisite(root);
	cout<<endl;

	// 层次遍历
	LevelVisite(root);
	cout<<endl;

	// 计算叶子节点数量
	cout<<CaculateLeafNum(root)<<endl;

	// 计算所有节点数量
	cout<<CaculateAllNodeNum(root)<<endl;

	// 计算二叉树深度
	cout<<CaculateDepth(root)<<endl;

	// 计算二叉树宽度
	cout<<CaculateWidth(root)<<endl;

	// 释放资源
	Release(root);

	system("pause");
	return 0;
}

其他操作：

 

Node* midLastToTree(const string& midIn, const string& lastIn)// 已知二叉树中序遍历和 
{                                             //后序遍历序列，求二叉树的二叉链表结构
	if (midIn.empty() || lastIn.empty())
	{
		return 0;
	}

	char rootC = *(lastIn.end() - 1); // 找出根结点
	// 把字符串midIn分成两部分 
	string::size_type rootIndex = midIn.find_first_of(rootC);
	string leftMidIn = midIn.substr(0, rootIndex);
	string rightMidIn = midIn.substr(rootIndex+1);
	// 把字符串lastIn也分成两部分 
	string leftLastIn;
	string rightLastIn;
	string::const_iterator curIter = lastIn.begin();
	string::const_iterator endIter = lastIn.end();
	for (; curIter!=endIter; ++curIter)
	{
		char c = *curIter;
		if (leftMidIn.find_first_of(c)!=string::npos)
		{
			leftLastIn.push_back(c);
		} else if (rightMidIn.find_first_of(c)!=string::npos)
		{
			rightLastIn.push_back(c);
		}
	}

	Node* tree = new Node;
	tree->c = rootC;
	// 递归
	tree->left = midLastToTree(leftMidIn, leftLastIn);
	tree->right = midLastToTree(rightMidIn, rightLastIn);
	return tree;
}
Node* firstMidToTree(const string& midIn, const string firstIn)// 已知二叉树中序遍历和
{                                               //先序遍历序列，求二叉树的二叉链表结构
	if (midIn.empty() || firstIn.empty())
	{
		return 0;
	}

	char rootC = *firstIn.begin();
	// 把字符串midIn分成两部分
	string::size_type rootIndex = midIn.find_first_of(rootC);
	string leftMidIn = midIn.substr(0, rootIndex);
	string rightMidIn = midIn.substr(rootIndex+1);
	// 把字符串firstIn分成两部分
	string leftFirstIn, rightFirstIn;
	string::const_iterator curIter = firstIn.begin();
	string::const_iterator endIter = firstIn.end();
	while (curIter != endIter)
	{
		char c = *curIter++;
		if (leftMidIn.find_first_of(c)!=string::npos)
		{
			leftFirstIn.push_back(c);
		} else if (rightMidIn.find_first_of(c)!=string::npos)
		{
			rightFirstIn.push_back(c);
		}
	}

	Node* tree = new Node;
	tree->c = rootC;
	// 递归
	tree->left = firstMidToTree(leftMidIn, leftFirstIn);
	tree->right = firstMidToTree(rightMidIn, rightFirstIn);
	return tree;
}

 

非递归后根遍历思路三：

 

void postOrder2(BinTree *root)    //非递归后序遍历
{
    stack<BTNode*> s;
    BinTree *p=root;
    BTNode *temp;
    while(p!=NULL||!s.empty())
    {
        while(p!=NULL)              //沿左子树一直往下搜索，直至出现没有左子树的结点 
        {
            BTNode *btn=(BTNode *)malloc(sizeof(BTNode));
            btn->btnode=p;
            btn->isFirst=true;
            s.push(btn);
            p=p->lchild;
        }
        if(!s.empty())
        {
            temp=s.top();
            s.pop();
            if(temp->isFirst==true)     //表示是第一次出现在栈顶 
             {
                temp->isFirst=false;
                s.push(temp);
                p=temp->btnode->rchild;    
            }
            else                        //第二次出现在栈顶 
             {
                cout<<temp->btnode->data<<" ";
                p=NULL;
            }
        }
    }    
}