Given a binary tree, find the leftmost value in the last row of the tree.
Example 1:
Input: 2 / \ 1 3 Output: 1
Example 2:
Input: 1 / \ 2 3 / / \ 4 5 6 / 7 Output: 7
Note: You may assume the tree (i.e., the given root node) is not NULL.
题目链接：https://leetcode.com/problems/find-bottom-left-tree-value/description/
题目分析：裸BFS，先右后左
/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode(int x) { val = x; } * } */ public class Solution { public int findBottomLeftValue(TreeNode root) { Queue<TreeNode> q = new LinkedList<>(); q.add(root); int ans = root.val; while (!q.isEmpty()) { TreeNode cur = q.poll(); ans = cur.val; if (cur.right != null) { q.add(cur.right); } if (cur.left != null) { q.add(cur.left); } } return ans; } }
