leetcode杂交刷题之始 -- Python3

# 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 inorderTraversal(self, root: Optional[TreeNode]) -> List[int]:
        stack, rst = [root], []
        while stack:
            i = stack.pop()
            if isinstance(i, TreeNode):
                stack.extend([i.right, i.val, i.left])
            elif isinstance(i, int):
                rst.append(i)
        return rst

        

# 直接拷贝最easy的方法
class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        hashtable = dict()
        for i, num in enumerate(nums):
            if target - num in hashtable:
                return[hashtable[target-num], i]
            hashtable[num] = i
        return []