Find Nearest Right Node in Binary Tree
给一个二叉树和一个node, 找到这个node在二叉树的右边的节点.
这个题要用层序扫描.
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/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode() {} * TreeNode(int val) { this.val = val; } * TreeNode(int val, TreeNode left, TreeNode right) { * this.val = val; * this.left = left; * this.right = right; * } * } */ class Solution { public TreeNode findNearestRightNode(TreeNode root, TreeNode u) { Queue<TreeNode> q = new LinkedList<>(); q.add(root); while(!q.isEmpty()) { int size = q.size(); boolean found = false; for(int i = 0; i < size; i++) { TreeNode node = q.poll(); if(found) return node; if(node.val == u.val) found = true; if(node.left != null) q.add(node.left); if(node.right != null) q.add(node.right); } } return null; } } |