LeetCode Binary Tree Level Order Traversal II

LeetCode解题之Binary Tree Level Order Traversal II

原题

[code]    3
   / \
  9  20
    /  \
   15   7

[code][
  [15,7],
  [9,20],
  [3]
]

解题思路

AC源码

[code]# 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 levelOrderBottom(self, root):
        """
        :type root: TreeNode
        :rtype: List[List[int]]
        """
        result = []
        if not root:
            return result
        curr_level = [root]
        while curr_level:
            level_result = []
            next_level = []
            for temp in curr_level:
                level_result.append(temp.val)
                if temp.left:
                    next_level.append(temp.left)
                if temp.right:
                    next_level.append(temp.right)
            result.append(level_result)
            curr_level = next_level
        result.reverse()
        return result

if __name__ == "__main__":
    None