二叉树-C++模板类

最新推荐文章于 2024-07-04 19:26:25 发布

Zou_Cuo

最新推荐文章于 2024-07-04 19:26:25 发布

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文章标签： c++ 开发语言数据结构

本文链接：https://blog.youkuaiyun.com/Zou_Cuo/article/details/137482008

版权

本文详细介绍了如何使用C++创建一个二叉树模板类，包括构造函数、析构函数以及前序、中序和后序遍历方法，并通过实例展示了如何构建和遍历一个二叉树。

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本文为二叉树C++模板类的“学习”代码，其中含构造、析构、插入、前序、中序‘后序遍历’等等。

#include <bits/stdc++.h>
using namespace std;

template <typename T>
struct TreeNode
{
    T val;
    TreeNode *left;
    TreeNode *right;
    TreeNode() : val(0), left(NULL), right(NULL) {}
    TreeNode(T x) : val(x), left(NULL), right(NULL) {}
};

template <typename T>
class Tree
{
private:
    TreeNode<T> *nodes;
    TreeNode<T> *root;
    size_t nodesize;

    TreeNode<T> *Create(T a[], int size, int nodeid, T nullnode);
    void visit(TreeNode<T> *node);
    void preorder(TreeNode<T> *node);
    void inorder(TreeNode<T> *node);
    void postorder(TreeNode<T> *node);
    void levelorder(TreeNode<T> *node);

public:
    Tree();
    Tree(int maxnodes);
    ~Tree();
    TreeNode<T> *GetTreeNode(int id);
    void CreateTree(T a[], int size, T nullnode);
    void preorderTree();
    void inorderTree();
    void postorderTree();
};

template <typename T>
Tree<T>::Tree()
{
    nodes = new TreeNode<T>[1000001];
}

template <typename T>
Tree<T>::Tree(int maxnodes)
{
    nodes = new TreeNode<T>[maxnodes];
}

template <typename T>
Tree<T>::~Tree()
{
    delete[] nodes;
}

template <typename T>
TreeNode<T> *Tree<T>::GetTreeNode(int id)
{
    return &nodes[id];
}

template <typename T>
TreeNode<T> *Tree<T>::Create(T a[], int size, int nodeid, T nullnode)
{
    if (nodeid >= size || a[nodeid] == nullnode)
    {
        return NULL;
    }
    TreeNode<T> *nownode = GetTreeNode(nodeid);
    nownode->val = a[nodeid];
    nownode->left = Create(a, size, nodeid * 2, nullnode);
    nownode->right = Create(a, size, nodeid * 2 + 1, nullnode);
    return nownode;
}

template <typename T>
void Tree<T>::visit(TreeNode<T> *node)
{
    cout << node->val;
}

template <typename T>
void Tree<T>::preorder(TreeNode<T> *node)
{
    if (node)
    {
        visit(node);
        preorder(node->left);
        preorder(node->right);
    }
}

template <typename T>
void Tree<T>::inorder(TreeNode<T> *node)
{
    if (node)
    {
        inorder(node->left);
        visit(node);
        inorder(node->right);
    }
}

template <typename T>
void Tree<T>::postorder(TreeNode<T> *node)
{
    if (node)
    {
        postorder(node->left);
        postorder(node->right);
        visit(node);
    }
}

template <typename T>
void Tree<T>::CreateTree(T a[], int size, T nullnode)
{
    root = Create(a, size, 1, nullnode);
}
template <typename T>
void Tree<T>::preorderTree()
{
    preorder(root);
}
template <typename T>
void Tree<T>::inorderTree()
{
    inorder(root);
}
template <typename T>
void Tree<T>::postorderTree()
{
    postorder(root);
}

int main()
{
    const char nullnode = '-';
    char a[15] = {
        nullnode, 'a', 'b', 'c', 'd',
        nullnode, 'e', 'f', 'g', 'h',
        nullnode, nullnode, nullnode, nullnode, 'i'};
    Tree<char> T[15];
    T->CreateTree(a, 15, nullnode);
    T->preorderTree();
    cout << "\n";
    T->inorderTree();
    cout << "\n";
    T->postorderTree();
    cout << "\n";
    return 0;
}

结果如下：