package bst;

import java.util.LinkedList;
import java.util.Queue;

public class BTDel {
    static Node root;
    
    static class Node{
        int key;
        Node left;
        Node right;
        
        Node(int key){
            this(key,null,null);
        }
        
        Node(
 
int key,Node left,Node right){
            this.key = key;
            this.left = left;
            this.right = right;
        }
    }
    
    public static void inorder(Node root) {
        if(root==null) {
            return;
        }
        inorder(root.left);
        System.out.print(root.key
 
+" ");
        inorder(root.right);
    }
    
    public static void deletDeepest(Node root,Node d_node) {
        Queue<Node> q = new LinkedList<Node>();
        Node temp;
        while(!q.isEmpty()) {
            temp = q.poll();
            if(temp.right != null) {
                
 
if(temp.right == d_node) {
                    temp.right = null;
                    d_node = null;
                    return;
                }else {
                    q.add(temp.right);
                }
            }
            if(temp.left != null) {
                if(temp.left == d_node) {
                    temp.left = null;
                    d_node = null;
                    return;
                }else {
                    q.add(temp.left);
                }
            }
        }
    } 
    
    public static void deletion(Node root,int key) {
        Queue<Node> q = new LinkedList<Node>();
        q.add(root);
        Node temp = null;
        Node key_node = null;
        while(!q.isEmpty()) {
            temp = q.poll();
            if(temp.key == key) {
                key_node = temp;
            }
            if(temp.left != null) {
                q.add(temp.left);
            }
            
            if(temp.right != null) {
                q.add(temp.right);
            }
        }
        
        int x = temp.key;
        deletDeepest(root,temp);
        key_node.key = x;
    }
    
    public static void main(String[] args) {
        Node root = new Node(10);
        root.left = new Node(11);
        root.left.left = new Node(7);
        root.left.right = new Node(12);
        root.right = new Node(9);
        root.right.left = new Node(15);
        root.right.right = new Node(8);
        System.out.println("Inorder traversal before deletion : ");
        inorder(root);
        
        int key = 11;
        
        deletion(root,key);
        
        System.out.println();
        
        inorder(root);
    }
    
    
}

二叉樹中的節點刪除-----按照最底層最右邊的節點收縮