二叉树的遍历(C++、STL)

之前没有使用C++的STL，写二叉树的遍历的时候基本都是选择用递归来实现，了解了C++标准模板库中的stack和queue后，发现遍历二叉树更加简单了，下面给出实例代码，通过实际验证发现这种方法很简洁，很方便

#include <vector>#include <iostream>#include <stack>#include <queue>using namespace std;struct BitNode{    int data;    BitNode *left, *right;    BitNode(int x) :data(x), left(0), right(0){}};

//创建二叉树函数，实际上安装先序遍历的方式来创建的，如果没有左(右)子数，则输入0void Create(BitNode *&root){    int key;    cin >> key;    if (key == 0)        root = NULL;    else    {        root = new BitNode(key);        Create(root->left);        Create(root->right);    }}void PreOrderTraversal(BitNode *root){    if (root)    {        cout << root->data << " ";        PreOrderTraversal(root->left);        PreOrderTraversal(root->right);    }}//深度优先搜索//利用栈，现将右子树压栈再将左子树压栈void DepthFirstSearch(BitNode *root){    stack<BitNode*> nodeStack;    nodeStack.push(root);    while (!nodeStack.empty())    {        BitNode *node = nodeStack.top();        cout << node->data << ' ';        nodeStack.pop();        if (node->right)        {            nodeStack.push(node->right);        }        if (node->left)        {            nodeStack.push(node->left);        }    }}//广度优先搜索void BreadthFirstSearch(BitNode *root){    queue<BitNode*> nodeQueue;    nodeQueue.push(root);    while (!nodeQueue.empty())    {        BitNode *node = nodeQueue.front();        cout << node->data << ' ';        nodeQueue.pop();        if (node->left)        {            nodeQueue.push(node->left);        }        if (node->right)        {            nodeQueue.push(node->right);        }    }}int  main(){    BitNode *root = NULL;    Create(root);    //前序遍历    PreOrderTraversal(root);    //深度优先遍历    cout << endl << "dfs" << endl;    DepthFirstSearch(root);    //广度优先搜索    cout << endl << "bfs" << endl;    BreadthFirstSearch(root);}