Two Sum Python Solution with Tests

lcpy gen -n 1   # by problem number
lcpy gen -s two_sum   # by problem name

Input: nums = [2,7,11,15], target = 9
Output: [0,1]

Input: nums = [3,2,4], target = 6
Output: [1,2]

Input: nums = [3,3], target = 6
Output: [0,1]

class Solution:
    # Time: O(n)
    # Space: O(n)
    def two_sum(self, nums: list[int], target: int) -> list[int]:
        seen: dict[int, int] = {}
        answers: list[list[int]] = []

        for i, num in enumerate(nums):
            complement = target - num
            if complement in seen:
                answer = [seen[complement], i]
                answers.append(answer)
            seen[num] = i

        if len(answers) > 1:
            raise ValueError(f"Found {len(answers)} answers in the solution: {answers}")

        return answers[0] if answers else []