class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        key_dict = {}
        for idx, num in enumerate(nums):
            if target-num in key_dict:
                # print("[{},{}]".format(key_dict[num], idx))
                # result.append(key_dict[num])
                # result.append(idx)
                return [key_dict[target-num],idx]
            key_dict[num] = idx
        return []