[LeetCode 75] Medium - 1161. Maximum Level Sum of a Binary Tree

1161. Maximum Level Sum of a Binary Tree

 

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def maxLevelSum(self, root: Optional[TreeNode]) -> int:
        if not root:
            return
        
        level = 1
        max_level = 1
        max_sum = -float("inf")
        
        que = deque([root])
        while que:
            level_size = len(que)
            level_sum = 0
            for _ in range(level_size):
                node = que.popleft()
                level_sum += node.val
                
                if node.left:
                    que.append(node.left)
                if node.right:
                    que.append(node.right)
            
            if level_sum > max_sum: # 해당 레벨 탐색 끝나면, 
                max_sum = level_sum
                max_level = level  
            level +=1

        return max_level

 

https://youtu.be/V1pCQo1BiVo?si=yBK28ajIyc61bpwA