AVL树每次c++重复关键字的倒排索引算法

#include <iostream>
using namespace std;

struct AVLNode {
    int key;
    int height;
    AVLNode* left;
    AVLNode* right;
};

int height(AVLNode* node) {
    if (node == nullptr) return 0;
    return node->height;
}

AVLNode* newNode(int key) {
    AVLNode* node = new AVLNode();
    node->key = key;
    node->left = nullptr;
    node->right = nullptr;
    node->height = 1;
    return node;
}

AVLNode* rightRotate(AVLNode* y) {
    AVLNode* x = y->left;
    AVLNode* T2 = x->right;
    x->right = y;
    y->left = T2;
    y->height = max(height(y->left), height(y->right)) + 1;
    x->height = max(height(x->left), height(x->right)) + 1;
    return x;
}

AVLNode* leftRotate(AVLNode* x) {
    AVLNode* y = x->right;
    AVLNode* T2 = y->left;
    y->left = x;
    x->right = T2;
    x->height = max(height(x->left), height(x->right)) + 1;
    y->height = max(height(y->left), height(y->right)) + 1;
    return y;
}

int getBalance(AVLNode* node) {
    if (node == nullptr) return 0;
    return height(node->left) - height(node->right);
}

AVLNode* insert(AVLNode* node, int key) {
    if (node == nullptr) return newNode(key);
    if (key < node->key) node->left = insert(node->left, key);
    else if (key > node->key) node->right = insert(node->right, key);
    else return node; // Duplicate keys not allowed
    node->height = 1 + max(height(node->left), height(node->right));
    int balance = getBalance(node);
    if (balance > 1 && key < node->left->key) return rightRotate(node);
    if (balance < -1 && key > node->right->key) return leftRotate(node);
    if (balance > 1 && key > node->left->key) {
        node->left = leftRotate(node->left);
        return rightRotate(node);
    }
    if (balance < -1 && key < node->right->key) {
        node->right = rightRotate(node->right);
        return leftRotate(node);
    }
    return node;
}

void preOrder(AVLNode* root) {
    if (root != nullptr) {
        cout << root->key << " ";
        preOrder(root->left);
        preOrder(root->right);
    }
}

int main() {
    AVLNode* root = nullptr;
    root = insert(root, 10);
    root = insert(root, 20);
    root = insert(root, 30);
    root = insert(root, 40);
    root = insert(root, 50);
    root = insert(root, 25);
    cout << "Preorder traversal of the constructed AVL tree is \n";
    preOrder(root);
    return 0;
}