package tree;

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

/**
 * 题目： 117. 填充每个节点的下一个右侧节点指针 II (buildTree)
 * 描述：给定两个整数数组 inorder 和 postorder ，其中 inorder 是二叉树的中序遍历， postorder 是同一棵树的后序遍历，请你构造并返回这颗 二叉树 。

 示例 2：
 输入：inorder = [9,3,15,20,7], postorder = [9,15,7,20,3]
 输出：[3,9,20,null,null,15,7]

 * 链接：https://leetcode.cn/problems/construct-binary-tree-from-inorder-and-postorder-traversal/
 */
public class Connect {
    class Node {
        public int val;
        public Node left;
        public Node right;
        public Node next;

        public Node() {}

        public Node(int _val) {
            val = _val;
        }

        public Node(int _val, Node _left, Node _right, Node _next) {
            val = _val;
            left = _left;
            right = _right;
            next = _next;
        }
    };
    public Node connect(Node root) {
        Queue<Node>queue=new LinkedList<>();
        if(root==null)return null;
        queue.offer(root);
        while (!queue.isEmpty()){
            int sz=queue.size();
            Node cur=queue.poll();
            if(cur.left!=null)queue.offer(cur.left);
            if(cur.right!=null)queue.offer(cur.right);
            for (int i = 1; i < sz; i++) {
                Node next =queue.poll();
                cur.next=next;
                cur=next;
                if(cur.left!=null)queue.offer(cur.left);
                if(cur.right!=null)queue.offer(cur.right);
            }
        }
        return root;
    }
}