二叉树遍历代码实例

二叉树遍历代码实例

//前序遍历：根节点->左子树->右子树
//中序遍历：左子树->根节点->右子树
//后序遍历：左子树->右子树->根节点

//定义数据类型可以用泛型
struct Data
{
    int hp;
};
//树的节点
struct Node
{
    Data data;
    Node* left;
    Node* right;
    Node(int num):left(NULL),right(NULL){}
    Node(){}
};

class Tree
{
public:
    Tree():root(NULL),len(0){}
    ~Tree(){}
    Node* root;
    void addNode(int num);
    void qian();
    void digui_qian(Node* node);
    void zhong();
    void digui_zhong(Node* node);
    void hou();
    void digui_hou(Node* node);
    void ceng();
private:
    int len;
    vector m_vec;    
};

//创建
void addNode(int num)
{
    len++;
    int n = len;
    Noed* node = new Node(num);
    if(n == 1)
    {
        root = node;
    }
    else
    {
        n = n/2;
        if(len%2)
        {
            m_vec[n-1]->right = node;
        }
        else
        {
            m_vec[n-1]->left = node;
        }
    }
    m_vec.push_back(node);
}

//前序遍历：根节点->左子树->右子树
//非递归
void qian()
{
    Node* node = root;
    stack sta;
    while(node || sta.size())
    {   
        if(node)
        {
            cout << node->data.hp << endl;
            if(node->right)
                sta.push(node->right)
            node = node->left;
        }
        else
        {
            node = sta.top();
            sta.pop();
        }
    }
}

//递归
void digui_qian(Node* node)
{
    if(node)
    {
        cout << node->date.hp <left);
        digui_xian(node->right);
    }
}

//中序遍历：左子树->根节点->右子树
//非递归
void zhong()
{
    Node* node = root;
    stack sta;
    if(node || sta.size())
    {
        if(node)
        {
            sta.push(node);
            node = node->left;
        }
        else
        {
            node = sta.top();
            sta.pop();
            cout << node->data.hp <right;
        }
    }
}

//递归
void digui_zhong(Node* node)
{
    if(node)
    {
        digui_xian(node->left);
        cout << node->date.hp <right);
    }
}


//后序遍历：左子树->右子树->根节点
//非递归
void hou()
{
    Node* node = root;
    Stack sta;
    while(node || sta.size())
    {
        if(node)
        {
            sta.push(node);
            node = node->left;
        }
        else
        {
            node = node->right;
            if(node)
                continue;

            node = sta.top();
            sta.pop();
            cout << node->data.hp << endl;

            while(sta.size() && sta.top()->right == node)
            {
                node = sta.top();
                sta.pop();
                cout << node->data.hp <right;
            else
                return;
        }
    }
}

//后序遍历：左子树->右子树->根节点
//递归
void digui_hou(Node* node)
{
    if(node)
    {
        digui(node->left);
        digui(node->right);
        cout << node->data.hp < que;
    que.push (root);

    while(que.size())
    {
        temp=que.front();
        que.pop();
        cout<data.hp<left )
            que.push( temp->left );

        if ( temp->right )
            que.push( temp->right );
    }
}