37 lines
1.1 KiB
Java
37 lines
1.1 KiB
Java
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package tree;
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import java.util.ArrayDeque;
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import java.util.ArrayList;
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import java.util.List;
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import java.util.Queue;
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/**
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* 题目： 199. 二叉树的右视图 (rightSideView)
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* 描述：给定一个二叉树的 根节点 root，想象自己站在它的右侧，按照从顶部到底部的顺序，返回从右侧所能看到的节点值。
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* 链接：https://leetcode.cn/problems/binary-tree-right-side-view/description/
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*/
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public class RightSideView {
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public List<Integer> rightSideView(TreeNode root) {
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Queue<TreeNode>queue=new ArrayDeque<>();
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List<Integer>res=new ArrayList<>();
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if(root==null)
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return res;
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queue.offer(root);
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while (!queue.isEmpty()){
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int size=queue.size();
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for (int i = 0; i < size; i++) {
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TreeNode temp=queue.poll();
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if(i==size-1)
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res.add(temp.val);
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if(temp.left!=null)
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queue.offer(temp.left);
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if(temp.right!=null)
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queue.offer(temp.right);
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}
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}
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return res;
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}
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}
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