测试AVL

AVL树：https://blog.csdn.net/qq_40794973/article/details/102978494

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349. 两个数组的交集 

https://leetcode-cn.com/problems/intersection-of-two-arrays/description/

/// Leetcode 349. Intersection of Two Arrays
/// https://leetcode.com/problems/intersection-of-two-arrays/description/

import java.util.ArrayList;
public class Solution {
    private class AVLTree, V> {
        private class Node{
            public K key;
            public V value;
            public Node left, right;
            public int height;
            public Node(K key, V value){
                this.key = key;
                this.value = value;
                left = null;
                right = null;
                height = 1;
            }
        }
        private Node root;
        private int size;
        public AVLTree(){
            root = null;
            size = 0;
        }
        public int getSize(){
            return size;
        }
        public boolean isEmpty(){
            return size == 0;
        }
        // 判断该二叉树是否是一棵二分搜索树
        public boolean isBST(){
            ArrayList keys = new ArrayList<>();
            inOrder(root, keys);
            for(int i = 1 ; i < keys.size() ; i ++) {
                if(keys.get(i - 1).compareTo(keys.get(i)) > 0) {
                    return false;
                }
            }
            return true;
        }
        private void inOrder(Node node, ArrayList keys){
            if(node == null) {
                return;
            }
            inOrder(node.left, keys);
            keys.add(node.key);
            inOrder(node.right, keys);
        }
        // 判断该二叉树是否是一棵平衡二叉树
        public boolean isBalanced(){
            return isBalanced(root);
        }
        // 判断以Node为根的二叉树是否是一棵平衡二叉树，递归算法
        private boolean isBalanced(Node node){
            if(node == null) {
                return true;
            }
            int balanceFactor = getBalanceFactor(node);
            if(Math.abs(balanceFactor) > 1) {
                return false;
            }
            return isBalanced(node.left) && isBalanced(node.right);
        }
        // 获得节点node的高度
        private int getHeight(Node node){
            if(node == null) {
                return 0;
            }
            return node.height;
        }
        // 获得节点node的平衡因子
        private int getBalanceFactor(Node node){
            if(node == null) {
                return 0;
            }
            return getHeight(node.left) - getHeight(node.right);
        }
        // 对节点y进行向右旋转操作，返回旋转后新的根节点x
        //        y                              x
        //       / \                           /   \
        //      x   T4     向右旋转 (y)        z     y
        //     / \       - - - - - - - ->    / \   / \
        //    z   T3                       T1  T2 T3 T4
        //   / \
        // T1   T2
        private Node rightRotate(Node y) {
            Node x = y.left;
            Node T3 = x.right;
            // 向右旋转过程
            x.right = y;
            y.left = T3;
            // 更新height
            y.height = Math.max(getHeight(y.left), getHeight(y.right)) + 1;
            x.height = Math.max(getHeight(x.left), getHeight(x.right)) + 1;
            return x;
        }
        // 对节点y进行向左旋转操作，返回旋转后新的根节点x
        //    y                             x
        //  /  \                          /   \
        // T1   x      向左旋转 (y)       y     z
        //     / \   - - - - - - - ->   / \   / \
        //   T2  z                     T1 T2 T3 T4
        //      / \
        //     T3 T4
        private Node leftRotate(Node y) {
            Node x = y.right;
            Node T2 = x.left;
            // 向左旋转过程
            x.left = y;
            y.right = T2;
            // 更新height
            y.height = Math.max(getHeight(y.left), getHeight(y.right)) + 1;
            x.height = Math.max(getHeight(x.left), getHeight(x.right)) + 1;
            return x;
        }
        // 向二分搜索树中添加新的元素(key, value)
        public void add(K key, V value){
            root = add(root, key, value);
        }
        // 向以node为根的二分搜索树中插入元素(key, value)，递归算法
        // 返回插入新节点后二分搜索树的根
        private Node add(Node node, K key, V value){
            if(node == null){
                size ++;
                return new Node(key, value);
            }
            if(key.compareTo(node.key) < 0) {
                node.left = add(node.left, key, value);
            } else if(key.compareTo(node.key) > 0) {
                node.right = add(node.right, key, value);
            } else { // key.compareTo(node.key) == 0
                node.value = value;
            }
            // 更新height
            node.height = 1 + Math.max(getHeight(node.left), getHeight(node.right));
            // 计算平衡因子
            int balanceFactor = getBalanceFactor(node);
            // 平衡维护
            // LL
            if (balanceFactor > 1 && getBalanceFactor(node.left) >= 0) {
                return rightRotate(node);
            }
            // RR
            if (balanceFactor < -1 && getBalanceFactor(node.right) <= 0) {
                return leftRotate(node);
            }
            // LR
            if (balanceFactor > 1 && getBalanceFactor(node.left) < 0) {
                node.left = leftRotate(node.left);
                return rightRotate(node);
            }
            // RL
            if (balanceFactor < -1 && getBalanceFactor(node.right) > 0) {
                node.right = rightRotate(node.right);
                return leftRotate(node);
            }
            return node;
        }
        // 返回以node为根节点的二分搜索树中，key所在的节点
        private Node getNode(Node node, K key){
            if(node == null) {
                return null;
            }
            if(key.equals(node.key)) {
                return node;
            } else if(key.compareTo(node.key) < 0) {
                return getNode(node.left, key);
            } else { // if(key.compareTo(node.key) > 0)
                return getNode(node.right, key);
            }
        }
        public boolean contains(K key){
            return getNode(root, key) != null;
        }
        public V get(K key){
            Node node = getNode(root, key);
            return node == null ? null : node.value;
        }
        public void set(K key, V newValue){
            Node node = getNode(root, key);
            if(node == null) {
                throw new IllegalArgumentException(key + " doesn't exist!");
            }
            node.value = newValue;
        }
        // 返回以node为根的二分搜索树的最小值所在的节点
        private Node minimum(Node node){
            if(node.left == null) {
                return node;
            }
            return minimum(node.left);
        }
        // 从二分搜索树中删除键为key的节点
        public V remove(K key){
            Node node = getNode(root, key);
            if(node != null){
                root = remove(root, key);
                return node.value;
            }
            return null;
        }
        private Node remove(Node node, K key){
            if( node == null ) {
                return null;
            }
            Node retNode;
            if( key.compareTo(node.key) < 0 ){
                node.left = remove(node.left , key);
                // return node;
                retNode = node;
            }
            else if(key.compareTo(node.key) > 0 ){
                node.right = remove(node.right, key);
                // return node;
                retNode = node;
            }
            else{   // key.compareTo(node.key) == 0
                // 待删除节点左子树为空的情况
                if(node.left == null){
                    Node rightNode = node.right;
                    node.right = null;
                    size --;
                    // return rightNode;
                    retNode = rightNode;
                }
                // 待删除节点右子树为空的情况
                else if(node.right == null){
                    Node leftNode = node.left;
                    node.left = null;
                    size --;
                    // return leftNode;
                    retNode = leftNode;
                }
                // 待删除节点左右子树均不为空的情况
                else{
                    // 找到比待删除节点大的最小节点, 即待删除节点右子树的最小节点
                    // 用这个节点顶替待删除节点的位置
                    Node successor = minimum(node.right);
                    //successor.right = removeMin(node.right);
                    successor.right = remove(node.right, successor.key);
                    successor.left = node.left;
                    node.left = node.right = null;
                    // return successor;
                    retNode = successor;
                }
            }
            if(retNode == null) {
                return null;
            }
            // 更新height
            retNode.height = 1 + Math.max(getHeight(retNode.left), getHeight(retNode.right));
            // 计算平衡因子
            int balanceFactor = getBalanceFactor(retNode);
            // 平衡维护
            // LL
            if (balanceFactor > 1 && getBalanceFactor(retNode.left) >= 0) {
                return rightRotate(retNode);
            }
            // RR
            if (balanceFactor < -1 && getBalanceFactor(retNode.right) <= 0) {
                return leftRotate(retNode);
            }
            // LR
            if (balanceFactor > 1 && getBalanceFactor(retNode.left) < 0) {
                retNode.left = leftRotate(retNode.left);
                return rightRotate(retNode);
            }
            // RL
            if (balanceFactor < -1 && getBalanceFactor(retNode.right) > 0) {
                retNode.right = rightRotate(retNode.right);
                return leftRotate(retNode);
            }
            return retNode;
        }
    }
    public int[] intersection(int[] nums1, int[] nums2) {
        AVLTree set = new AVLTree<>();
        for(int num: nums1) {
            set.add(num, null);
        }
        ArrayList list = new ArrayList<>();
        for(int num: nums2){
            if(set.contains(num)){
                list.add(num);
                set.remove(num);
            }
        }
        int[] res = new int[list.size()];
        for(int i = 0 ; i < list.size() ; i ++) {
            res[i] = list.get(i);
        }
        return res;
    }
}

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350. 两个数组的交集 II

https://leetcode-cn.com/problems/intersection-of-two-arrays-ii/description/ 

/// Leetcode 350. Intersection of Two Arrays II
/// https://leetcode-cn.com/problems/intersection-of-two-arrays-ii/description/
import java.util.ArrayList;
public class Solution {
    private class AVLTree, V> {
        private class Node{
            public K key;
            public V value;
            public Node left, right;
            public int height;
            public Node(K key, V value){
                this.key = key;
                this.value = value;
                left = null;
                right = null;
                height = 1;
            }
        }
        private Node root;
        private int size;
        public AVLTree(){
            root = null;
            size = 0;
        }
        public int getSize(){
            return size;
        }
        public boolean isEmpty(){
            return size == 0;
        }
        // 判断该二叉树是否是一棵二分搜索树
        public boolean isBST(){
            ArrayList keys = new ArrayList<>();
            inOrder(root, keys);
            for(int i = 1 ; i < keys.size() ; i ++) {
                if(keys.get(i - 1).compareTo(keys.get(i)) > 0) {
                    return false;
                }
            }
            return true;
        }
        private void inOrder(Node node, ArrayList keys){
            if(node == null) {
                return;
            }
            inOrder(node.left, keys);
            keys.add(node.key);
            inOrder(node.right, keys);
        }
        // 判断该二叉树是否是一棵平衡二叉树
        public boolean isBalanced(){
            return isBalanced(root);
        }
        // 判断以Node为根的二叉树是否是一棵平衡二叉树，递归算法
        private boolean isBalanced(Node node){
            if(node == null){
                return true;
            }
            int balanceFactor = getBalanceFactor(node);
            if(Math.abs(balanceFactor) > 1) {
                return false;
            }
            return isBalanced(node.left) && isBalanced(node.right);
        }
        // 获得节点node的高度
        private int getHeight(Node node){
            if(node == null) {
                return 0;
            }
            return node.height;
        }
        // 获得节点node的平衡因子
        private int getBalanceFactor(Node node){
            if(node == null) {
                return 0;
            }
            return getHeight(node.left) - getHeight(node.right);
        }
        // 对节点y进行向右旋转操作，返回旋转后新的根节点x
        //        y                              x
        //       / \                           /   \
        //      x   T4     向右旋转 (y)        z     y
        //     / \       - - - - - - - ->    / \   / \
        //    z   T3                       T1  T2 T3 T4
        //   / \
        // T1   T2
        private Node rightRotate(Node y) {
            Node x = y.left;
            Node T3 = x.right;
            // 向右旋转过程
            x.right = y;
            y.left = T3;
            // 更新height
            y.height = Math.max(getHeight(y.left), getHeight(y.right)) + 1;
            x.height = Math.max(getHeight(x.left), getHeight(x.right)) + 1;

            return x;
        }
        // 对节点y进行向左旋转操作，返回旋转后新的根节点x
        //    y                             x
        //  /  \                          /   \
        // T1   x      向左旋转 (y)       y     z
        //     / \   - - - - - - - ->   / \   / \
        //   T2  z                     T1 T2 T3 T4
        //      / \
        //     T3 T4
        private Node leftRotate(Node y) {
            Node x = y.right;
            Node T2 = x.left;
            // 向左旋转过程
            x.left = y;
            y.right = T2;
            // 更新height
            y.height = Math.max(getHeight(y.left), getHeight(y.right)) + 1;
            x.height = Math.max(getHeight(x.left), getHeight(x.right)) + 1;
            return x;
        }
        // 向二分搜索树中添加新的元素(key, value)
        public void add(K key, V value){
            root = add(root, key, value);
        }
        // 向以node为根的二分搜索树中插入元素(key, value)，递归算法
        // 返回插入新节点后二分搜索树的根
        private Node add(Node node, K key, V value){
            if(node == null){
                size ++;
                return new Node(key, value);
            }
            if(key.compareTo(node.key) < 0) {
                node.left = add(node.left, key, value);
            } else if(key.compareTo(node.key) > 0) {
                node.right = add(node.right, key, value);
            } else {// key.compareTo(node.key) == 0
                node.value = value;
            }
            // 更新height
            node.height = 1 + Math.max(getHeight(node.left), getHeight(node.right));
            // 计算平衡因子
            int balanceFactor = getBalanceFactor(node);
            // 平衡维护
            // LL
            if (balanceFactor > 1 && getBalanceFactor(node.left) >= 0) {
                return rightRotate(node);
            }
            // RR
            if (balanceFactor < -1 && getBalanceFactor(node.right) <= 0) {
                return leftRotate(node);
            }
            // LR
            if (balanceFactor > 1 && getBalanceFactor(node.left) < 0) {
                node.left = leftRotate(node.left);
                return rightRotate(node);
            }
            // RL
            if (balanceFactor < -1 && getBalanceFactor(node.right) > 0) {
                node.right = rightRotate(node.right);
                return leftRotate(node);
            }
            return node;
        }
        // 返回以node为根节点的二分搜索树中，key所在的节点
        private Node getNode(Node node, K key){
            if(node == null) {
                return null;
            }
            if(key.equals(node.key)) {
                return node;
            } else if(key.compareTo(node.key) < 0) {
                return getNode(node.left, key);
            } else { // if(key.compareTo(node.key) > 0)
                return getNode(node.right, key);
            }
        }
        public boolean contains(K key){
            return getNode(root, key) != null;
        }
        public V get(K key){
            Node node = getNode(root, key);
            return node == null ? null : node.value;
        }
        public void set(K key, V newValue){
            Node node = getNode(root, key);
            if(node == null) {
                throw new IllegalArgumentException(key + " doesn't exist!");
            }
            node.value = newValue;
        }
        // 返回以node为根的二分搜索树的最小值所在的节点
        private Node minimum(Node node){
            if(node.left == null) {
                return node;
            }
            return minimum(node.left);
        }
        // 从二分搜索树中删除键为key的节点
        public V remove(K key){
            Node node = getNode(root, key);
            if(node != null){
                root = remove(root, key);
                return node.value;
            }
            return null;
        }
        private Node remove(Node node, K key){
            if( node == null ) {
                return null;
            }
            Node retNode;
            if( key.compareTo(node.key) < 0 ){
                node.left = remove(node.left , key);
                // return node;
                retNode = node;
            }
            else if(key.compareTo(node.key) > 0 ){
                node.right = remove(node.right, key);
                // return node;
                retNode = node;
            }
            else{   // key.compareTo(node.key) == 0
                // 待删除节点左子树为空的情况
                if(node.left == null){
                    Node rightNode = node.right;
                    node.right = null;
                    size --;
                    // return rightNode;
                    retNode = rightNode;
                }
                // 待删除节点右子树为空的情况
                else if(node.right == null){
                    Node leftNode = node.left;
                    node.left = null;
                    size --;
                    // return leftNode;
                    retNode = leftNode;
                }
                // 待删除节点左右子树均不为空的情况
                else{
                    // 找到比待删除节点大的最小节点, 即待删除节点右子树的最小节点
                    // 用这个节点顶替待删除节点的位置
                    Node successor = minimum(node.right);
                    //successor.right = removeMin(node.right);
                    successor.right = remove(node.right, successor.key);
                    successor.left = node.left;
                    node.left = node.right = null;
                    // return successor;
                    retNode = successor;
                }
            }
            if(retNode == null) {
                return null;
            }
            // 更新height
            retNode.height = 1 + Math.max(getHeight(retNode.left), getHeight(retNode.right));
            // 计算平衡因子
            int balanceFactor = getBalanceFactor(retNode);
            // 平衡维护
            // LL
            if (balanceFactor > 1 && getBalanceFactor(retNode.left) >= 0) {
                return rightRotate(retNode);
            }
            // RR
            if (balanceFactor < -1 && getBalanceFactor(retNode.right) <= 0) {
                return leftRotate(retNode);
            }
            // LR
            if (balanceFactor > 1 && getBalanceFactor(retNode.left) < 0) {
                retNode.left = leftRotate(retNode.left);
                return rightRotate(retNode);
            }
            // RL
            if (balanceFactor < -1 && getBalanceFactor(retNode.right) > 0) {
                retNode.right = rightRotate(retNode.right);
                return leftRotate(retNode);
            }
            return retNode;
        }
    }
    public int[] intersect(int[] nums1, int[] nums2) {
        AVLTree map = new AVLTree<>();
        for(int num: nums1){
            if(!map.contains(num)) {
                map.add(num, 1);
            } else {
                map.add(num, map.get(num) + 1);
            }
        }
        ArrayList res = new ArrayList<>();
        for(int num: nums2){
            if(map.contains(num)){
                res.add(num);
                map.add(num, map.get(num) - 1);
                if(map.get(num) == 0) {
                    map.remove(num);
                }
            }
        }
        int[] ret = new int[res.size()];
        for(int i = 0 ; i < res.size() ; i ++) {
            ret[i] = res.get(i);
        }
        return ret;
    }
}