c++编写二叉树的基本操作

二叉树的基本操作包括创建、插入、删除、查找、遍历等，下面是C++代码示例：

#include <iostream>
#include <queue>
using namespace std;

// 定义二叉树节点的结构体
struct TreeNode {
    int val;
    TreeNode* left;
    TreeNode* right;
    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
};

// 创建二叉树
TreeNode* createTree() {
    int val;
    cin >> val;
    if (val == -1) {
        return nullptr;
    }
    TreeNode* root = new TreeNode(val);
    root->left = createTree();
    root->right = createTree();
    return root;
}

// 插入节点
void insertNode(TreeNode* root, int val) {
    if (root == nullptr) {
        return;
    }
    queue<TreeNode*> q;
    q.push(root);
    while (!q.empty()) {
        TreeNode* cur = q.front();
        q.pop();
        if (cur->left == nullptr) {
            cur->left = new TreeNode(val);
            return;
        }
        if (cur->right == nullptr) {
            cur->right = new TreeNode(val);
            return;
        }
        q.push(cur->left);
        q.push(cur->right);
    }
}

// 删除节点
TreeNode* deleteNode(TreeNode* root, int val) {
    if (root == nullptr) {
        return nullptr;
    }
    if (root->val == val) {
        if (root->left == nullptr && root->right == nullptr) {
            delete root;
            return nullptr;
        }
        if (root->left == nullptr) {
            TreeNode* temp = root->right;
            delete root;
            return temp;
        }
        if (root->right == nullptr) {
            TreeNode* temp = root->left;
            delete root;
            return temp;
        }
        TreeNode* minNode = root->right;
        while (minNode->left != nullptr) {
            minNode = minNode->left;
        }
        root->val = minNode->val;
        root->right = deleteNode(root->right, minNode->val);
    } else if (root->val > val) {
        root->left = deleteNode(root->left, val);
    } else {
        root->right = deleteNode(root->right, val);
    }
    return root;
}

// 查找节点
TreeNode* searchNode(TreeNode* root, int val) {
    if (root == nullptr || root->val == val) {
        return root;
    }
    if (root->val > val) {
        return searchNode(root->left, val);
    } else {
        return searchNode(root->right, val);
    }
}

// 前序遍历
void preOrder(TreeNode* root) {
    if (root == nullptr) {
        return;
    }
    cout << root->val << " ";
    preOrder(root->left);
    preOrder(root->right);
}

// 中序遍历
void inOrder(TreeNode* root) {
    if (root == nullptr) {
        return;
    }
    inOrder(root->left);
    cout << root->val << " ";
    inOrder(root->right);
}

// 后序遍历
void postOrder(TreeNode* root) {
    if (root == nullptr) {
        return;
    }
    postOrder(root->left);
    postOrder(root->right);
    cout << root->val << " ";
}

int main() {
    // 创建二叉树
    TreeNode* root = createTree();

    // 插入节点
    insertNode(root, 10);

    // 删除节点
    root = deleteNode(root, 5);

    // 查找节点
    TreeNode* node = searchNode(root, 3);
    cout << "search node: " << node->val << endl;

    // 遍历二叉树
    cout << "preorder: ";
    preOrder(root);
    cout << endl;

    cout << "inorder: ";
    inOrder(root);
    cout << endl;

    cout << "postorder: ";
    postOrder(root);
    cout << endl;

    return 0;
}

以上代码包含了二叉树的创建、插入、删除、查找以及前序、中序、后序遍历等基本操作。