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.
/**
* 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;
}
}