Two Sum and the use of Dictionary (Easy) | LeetCode Practice #1

####Double FOR Loops (Runtime: 2100ms, Memory: 13.3MB)

    #DECLARE nums: ARRAY of INTEGER

    #DECLARE target: INTEGER

class Solution:

    def twoSum(self, nums, target):

        Length = len(nums)

        for i in range(Length - 1):

            for j in range((i + 1), Length):

                if nums[i] + nums[j] == target:

                    return i, j

        return None







####Hashing Algorithm (Runtime: 0ms, Memory: 12.9MB)

    #DECLARE nums: ARRAY of INTEGER

    #DECLARE target: INTEGER

class Solution:

    def twoSum(self, nums, target):

        Seen = {}

        for i, Value in enumerate(nums):

            if (target - Value) in Seen:

                return Seen[target - Value], i

            Seen[Value] = i

        return None