题解 | #求二叉树的层序遍历#

# class TreeNode:
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

#
# 
# @param root TreeNode类 
# @return int整型二维数组
#
class Solution:
    def levelOrder(self , root ):
        # write code here
        res = []
        nodeL = []
        if root is None: return
        nodeL.append(root)
        count = 1
        while len(nodeL)>0:
            tres = []
            while count>0:
                node = nodeL.pop(0)
                tres.append(node.val)
                count-= 1
                if node.left:
                    nodeL.append(node.left)
                if node.right:
                    nodeL.append(node.right)
            res.append(tres)
            count = len(nodeL)
        return res