二叉树特点

左节点值小于根节点值，右节点值大于根节点

  public class BinaryTree {

    private Node root;
    @Data
    private static class Node {
        private int data;
        private Node left;
        private Node right;

        public Node(int data){
            this.data = data;
        }
    }


    public Node find(int key){
        Node current = root;
        while(current != null){
            if(current.data > key){
                current = current.left;
            }
            if(current.data < key){
                current = current.right;
            }
            if(current.data == key){
                return current;
            }
        }
        return null;
    }

    public boolean insert(int data){
        Node newNode = new Node(data);
        if(root == null){
            root =  newNode;
            return true;
        }else{
            Node current = root;
            Node parent = null;
            while (current != null){
                 parent = current;
                if(current.data > data){
                    current = current.left;
                    if(current == null){
                        parent.left = newNode;
                        return true;
                    }

                } else{
                    current = current.right;
                    if(current == null){
                        parent.right = newNode;
                        return true;
                    }
                }
            }
        }
        return false;
    }

    public Node findMax(){
        Node current = root;
        while(current != null){
            current = current.right;
        }
        return current;
    }

    public Node findMin(){
        Node current = root;
        while (current != null) {
            current = current.left;
        }
        return current;
    }

    //删除没有子节点的节点
    public boolean delete(int key){
        Node current = root;
        Node parent = current;
        boolean isLeft = false;
        while (current.data != key){
            parent = current;
            if(current.data > key){
                isLeft = true;
                current = current.left;
            }else {
                isLeft = false;
                current = current.right;
            }
            if(current == null){
                return false;
            }
        }
        if(current.left == null && current.right == null){
            if(current == root){
                root = null;
            }
            if(isLeft){
                parent.left = null;
            }else{
                parent.right = null;
            }
            return true;
        }
        return false;

    }
}