【LeetCode】515. Find Largest Value in Each Tree Row【E】【87】

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.

广搜，对每层，直接记录最小的元素就行了

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class 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]