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]
Subscribe to see which companies asked this question.廣搜，對每層，直接記錄最小的元素就行了
# Definition for a binary tree node.# class TreeNode(object):#     def __init__(self, x):#         self.val = x#         self.left = None#         self.right = Noneclass Solution(object):    def largestValues(self, root):                if not root:            return []                res = [root.val]                s = [root]                while s:            tval = - 1 << 32            tnode = []            for i in s:                if i.left != None:                    tnode += i.left,                    tval = max(tval,i.left.val)                if i.right != None:                    tnode += i.right,                    tval = max(tval,i.right.val)            s = tnode[:]            #PRint s            res += tval,        return res[:-1]