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:
    ret = []
    def levelOrder(self , root ):
        # write code here
        if root:
            self.ret.append([root.val])
            self.deep([root])
        return self.ret

    def deep(self, nodes):
        li = []
        nextNodes = []
        for node in nodes:
            if node.left:
                li.append(node.left.val)
                nextNodes.append(node.left)
            if node.right:
                li.append(node.right.val)
                nextNodes.append(node.right)
        if not li: return
        self.ret.append(li)
        self.deep(nextNodes)