Leetcode algorithm: Find largest Value in each Tree Row

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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]


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


This title describes:
give us a binary tree root node that returns an array of the maximum values for each layer


thought:
breadth-first traversal, placing the maximum value of each layer into the result list

python implementations:

1 classsolution (object):2     deflargestvalues (self, root):3         """4 : Type Root:treenode5 : Rtype:list[int]6         """7         if  notRoot:8             return []9levels =[[Root]]TenValues =[[Root.val]] One          forLevelinchlevels: ANext_level = [] -Value = [] -              forNodeinchLevel : the                 ifNode.left is  notNone: - next_level.append (node.left) - value.append (node.left.val) -                 ifNode.right is  notNone: + next_level.append (node.right) - value.append (node.right.val) +             ifNext_level: A levels.append (next_level) at values.append (value) -res = [] -          forVinchvalues: - res.append (Max (v)) -         returnRes

Streamline the code:

1 classsolution (object):2     deflargestvalues (self, root):3         """4 : Type Root:treenode5 : Rtype:list[int]6         """7Values = []8Level =[Root]9          whileAny (level):TenValues.append (Max ([I.val forIinchLevel ]) ) Onelevel = [Child forNodeinchLevel forChildinch[Node.left, Node.right]ifChild is  notNone] A         returnValues

Leetcode algorithm: Find largest Value in each Tree Row