So implementieren Sie den Rot-Schwarz-Baum-Algorithmus mit Java

// 定义红黑树节点类
class Node {
    int key;
    Node parent;
    Node left;
    Node right;
    boolean isRed; // 红色节点为true，黑色节点为false

    public Node(int key) {
        this.key = key;
        this.parent = null;
        this.left = null;
        this.right = null;
        this.isRed = true; // 默认插入的节点为红色节点
    }
}

// 定义红黑树类
class RedBlackTree {
    private Node root;
    private final Node NIL;

    public RedBlackTree() {
        NIL = new Node(-1); // 定义一个表示NIL节点的对象
        NIL.isRed = false; // NIL节点为黑色节点
        root = NIL;
    }

    // 插入节点
    public void insert(int key) {
        Node node = new Node(key);
        Node current = root;
        Node parent = null;
        while (current != NIL) {
            parent = current;
            if (key < current.key) {
                current = current.left;
            } else {
                current = current.right;
            }
        }
        node.parent = parent;
        if (parent == null) {
            root = node;
        } else if (key < parent.key) {
            parent.left = node;
        } else {
            parent.right = node;
        }
        node.left = NIL;
        node.right = NIL;
        node.isRed = true;
        insertFixup(node);
    }

    // 插入修复
    private void insertFixup(Node node) {
        while (node.parent.isRed) {
            if (node.parent == node.parent.parent.left) {
                Node uncle = node.parent.parent.right;
                if (uncle.isRed) { // Case 1: 叔节点为红色
                    node.parent.isRed = false;
                    uncle.isRed = false;
                    node.parent.parent.isRed = true;
                    node = node.parent.parent;
                } else {
                    if (node == node.parent.right) {
                        node = node.parent;
                        leftRotate(node);
                    }
                    node.parent.isRed = false;
                    node.parent.parent.isRed = true;
                    rightRotate(node.parent.parent);
                }
            } else {
                Node uncle = node.parent.parent.left;
                if (uncle.isRed) { // Case 1: 叔节点为红色
                    node.parent.isRed = false;
                    uncle.isRed = false;
                    node.parent.parent.isRed = true;
                    node = node.parent.parent;
                } else {
                    if (node == node.parent.left) {
                        node = node.parent;
                        rightRotate(node);
                    }
                    node.parent.isRed = false;
                    node.parent.parent.isRed = true;
                    leftRotate(node.parent.parent);
                }
            }
        }
        root.isRed = false;
    }

    // 左旋转
    private void leftRotate(Node node) {
        Node child = node.right;
        node.right = child.left;
        if (child.left != NIL) {
            child.left.parent = node;
        }
        child.parent = node.parent;
        if (node.parent == NIL) {
            root = child;
        } else if (node == node.parent.left) {
            node.parent.left = child;
        } else {
            node.parent.right = child;
        }
        child.left = node;
        node.parent = child;
    }

    // 右旋转
    private void rightRotate(Node node) {
        Node child = node.left;
        node.left = child.right;
        if (child.right != NIL) {
            child.right.parent = node;
        }
        child.parent = node.parent;
        if (node.parent == NIL) {
            root = child;
        } else if (node == node.parent.right) {
            node.parent.right = child;
        } else {
            node.parent.left = child;
        }
        child.right = node;
        node.parent = child;
    }

    // 查找节点
    public Node search(int key) {
        Node current = root;
        while (current != NIL && key != current.key) {
            if (key < current.key) {
                current = current.left;
            } else {
                current = current.right;
            }
        }
        return current;
    }
}

// 测试红黑树的代码
public class Main {
    public static void main(String[] args) {
        RedBlackTree tree = new RedBlackTree();
        tree.insert(10);
        tree.insert(20);
        tree.insert(30);
        tree.insert(40);
        tree.insert(50);
        tree.insert(60);
        tree.insert(70);
        Node node = tree.search(50);
        if (node != tree.NIL) {
            System.out.println("找到了节点：" + node.key);
        } else {
            System.out.println("没有找到节点");
        }
    }
}