"""1. Two Sum
https://leetcode.com/problems/two-sum/

Given an array of integers, return indices of the two numbers such that
they add up to a specific target.

You may assume that each input would have exactly one solution,
and you may not use the same element twice.

Example:

Given nums = [2, 7, 11, 15], target = 9,

Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].
"""
from typing import List


class Solution:
    def two_sum(self, nums: List[int], target: int) -> List[int]:
        store = dict()
        for i, num in enumerate(nums):
            if target - num in store:
                return [store[target - num], i]
            store[num] = i
