You need to find the largest value in each row of a binary tree.
Example:
Input:
1
/ 3 2
/ \ \
5 3 9
Output: [1, 3, 9]
题意：找出二叉树一层的最大值
解法：用BFS的方式遍历每一层
class Solution(object):def largestValues(self, root):""":type root: TreeNode:rtype: List[int]"""result = []if not root:return resultqueue = [root]while queue:count = len(queue)res = -2147483648for i in range(count):curNode = queue.pop(0)res = max(curNode.val, res)if curNode.left:queue.append(curNode.left)if curNode.right:queue.append(curNode.right)result.append(res)return result
515. Find Largest Value in Each Tree Row 二叉树每一层的最大值
原文：http://www.cnblogs.com/xiejunzhao/p/7397883.html