AVL树( C++)

来源：互联网发布：windows组件向导编辑：程序博客网时间：2024/06/08 06:43
#include <iostream>#include <queue>using namespace std;struct Node {    int val;    Node *left = nullptr;    Node *right = nullptr;    int factor = 0;    Node(int i) : val(i) {};};class AVLTree {public:    void balance(Node *&node) {        if (node->factor == 2) {            if (node->left->factor == 1) {                Node *temp = node->left;                node->left = temp->right;                node->factor = 0;                temp->right = node;                temp->factor = 0;                node = temp;            } else if (node->left->factor == -1) {                Node *temp = node->left;                node->left = temp->right;                temp->right = nullptr;                node->left->left = temp;                node->left->factor = 1;                if (node->left->right == nullptr) {                    node->left->left->factor = 0;                } else {                    node->left->left->factor = 1;                }                balance(node);            }        } else if (node->factor == -2) {            if (node->right->factor == -1) {                Node *temp = node->right;                node->right = temp->left;                node->factor = 0;                temp->left = node;                temp->factor = 0;                node = temp;            } else if (node->right->factor == 1) {                Node *temp = node->right;                node->right = temp->left;                temp->left = nullptr;                node->right->right = temp;                node->right->factor = -1;                if (node->right->left == nullptr) {                    node->right->right->factor = 0;                } else {                    node->right->right->factor = -1;                }                balance(node);            }        }    }    void insert(Node *&node, int val, bool &adjust) {        if (node == nullptr) return;        if (val < node->val) {            if (node->left == nullptr) {                Node *temp = new Node(val);                node->left = temp;                ++node->factor;                //高度不变，左右平衡                if (node->factor == 0) adjust = false;            } else {                insert(node->left, val, adjust);                //回溯，调整平衡因子                if (adjust) ++node->factor;            }        } else if (val > node->val) {            if (node->right == nullptr) {                Node *temp = new Node(val);                node->right = temp;                --node->factor;                //高度不变，左右平衡                if (node->factor == 0) adjust = false;            } else {                insert(node->right, val, adjust);                //回溯，调整平衡因子                if (adjust) --node->factor;            }        } else {            perror("same value");            exit(1);        }        if (node->factor == 2 || node->factor == -2) {            balance(node);            //不管是LL还是LR全部旋转之后的高度都是不变的，可画图验证            adjust = false;        }    }    void insert(int val) {        bool adjust = true;        insert(root, val, adjust);    }    bool remove(Node *&node, int val, bool &shorter) {        if (node == nullptr) return false;        if (val < node->val) {            if (remove(node->left, val, shorter)) {                return false;            }            if (shorter) {                switch (node->factor) {                    case 1:                        node->factor = 0;                        shorter = true;                        break;                    case -1:                        shorter = node->right->factor != 0;                        node->factor = -2;                        balance(node);                        break;                    case 0:                        node->factor = -1;                        shorter = false;                        break;                    default:                        break;                }            }        } else if (val > node->val) {            if (remove(node->right, val, shorter)) {                return false;            }            if (shorter) {                switch (node->factor) {                    case 1:                        shorter = node->left->factor != 0;                        node->factor = 2;                        balance(node);                        break;                    case -1:                        node->factor = 0;                        shorter = true;                        break;                    case 0:                        node->factor = 1;                        shorter = false;                        break;                    default:                        break;                }            }        } else {            if (node->left == nullptr) {                Node *temp = node;                node = node->right;                delete temp;                shorter = true;            } else if (node->right == nullptr) {                Node *temp = node;                node = node->left;                delete temp;                shorter = true;            } else {                Node *temp = node->right;                while (temp->left != nullptr) {                    temp = temp->left;                }                node->val = temp->val;                remove(node->right, temp->val, shorter);                if (shorter) {                    switch (node->factor) {                        case 1:                            shorter = node->left->factor != 0;                            node->factor = 2;                            balance(node);                            break;                        case -1:                            node->factor = 0;                            shorter = true;                            break;                        case 0:                            node->factor = 1;                            shorter = false;                            break;                        default:                            break;                    }                }            }        }        return true;    }    void remove(int val) {        bool shorter = false;        remove(root, val, shorter);    }    Node *create(int arr[], int len) {        for (int i = 0; i < len; ++i) {            if (this->root == nullptr) {                root = new Node(arr[i]);            } else {                insert(arr[i]);            }        }        return root;    }    void level_travel() {        queue<Node *> q;        q.push(root);        while (!q.empty()) {            Node *n = q.front();            q.pop();            cout << n->val << " ";            if (n->left != nullptr) {                q.push(n->left);            }            if (n->right != nullptr) {                q.push(n->right);            }        }        cout << "\n";    }private:    Node *root = nullptr;};int main() {    int len = 10;    int nodes[10] = { 5,13,7,9,1,3,10,15,20,25 };    AVLTree avl;    avl.create(nodes, len);    avl.level_travel();    avl.remove(15);    avl.level_travel();    return 0;}
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