[LeetCode][Python3] 94. Binary Tree Inorder Traversal

snoopybox 2019. 1. 3. 01:26

Problem :

https://leetcode.com/problems/binary-tree-inorder-traversal/

My Solution :

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

class Solution:
    def inorderTraversal(self, root):
        """
        :type root: TreeNode
        :rtype: List[int]
        """
        ret = []
        stack = []
        curr = root
        while stack or curr:
            if curr:
                stack.append(curr)
                curr = curr.left
            else:
                curr = stack.pop()
                ret.append(curr.val)
                curr = curr.right
        return ret

My Solution2 :

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

class Solution:
    def inorderTraversal(self, root):
        """
        :type root: TreeNode
        :rtype: List[int]
        """
        ret = []

        def inorder(node):
            if node:
                inorder(node.left)
                ret.append(node.val)
                inorder(node.right)

        inorder(root)
        return ret