1_Two_Sum.py

# time : O(N) on average
# space: O(N)
class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        pos = {}

        size = len(nums)
        for i in range(0, size):
            complement = target - nums[i]
            if complement in pos:
                return [i, pos[complement]]
            pos[nums[i]] = i