56 lines
1.6 KiB
Java
56 lines
1.6 KiB
Java
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package tree;
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import java.util.LinkedList;
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import java.util.Queue;
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/**
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* 题目： 117. 填充每个节点的下一个右侧节点指针 II (buildTree)
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* 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 。
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示例 2：
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输入：inorder = [9,3,15,20,7], postorder = [9,15,7,20,3]
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输出：[3,9,20,null,null,15,7]
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* 链接：https://leetcode.cn/problems/construct-binary-tree-from-inorder-and-postorder-traversal/
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*/
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public class Connect {
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class Node {
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public int val;
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public Node left;
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public Node right;
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public Node next;
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public Node() {}
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public Node(int _val) {
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val = _val;
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}
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public Node(int _val, Node _left, Node _right, Node _next) {
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val = _val;
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left = _left;
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right = _right;
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next = _next;
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}
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};
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public Node connect(Node root) {
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Queue<Node>queue=new LinkedList<>();
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if(root==null)return null;
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queue.offer(root);
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while (!queue.isEmpty()){
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int sz=queue.size();
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Node cur=queue.poll();
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if(cur.left!=null)queue.offer(cur.left);
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if(cur.right!=null)queue.offer(cur.right);
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for (int i = 1; i < sz; i++) {
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Node next =queue.poll();
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cur.next=next;
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cur=next;
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if(cur.left!=null)queue.offer(cur.left);
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if(cur.right!=null)queue.offer(cur.right);
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}
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}
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return root;
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}
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}
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