Two Sum

description easy

accepted(one bang)

class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        for i in nums:
            we_want = target - i
            temp = nums[nums.index(i)+1:]
            if we_want in temp:
                index = temp.index(we_want) + nums.index(i)+1
                return [nums.index(i), index]

faster solution using hashmap:

class Solution(object):
    def twoSum(self, nums, target):
        """
        :type nums: List[int]
        :type target: int
        :rtype: List[int]
        """
        map = {}
        for i,n in enumerate(nums):
            diff = target - n
            if diff in map:
                return(map[diff], i)
            map[n] = i
        return

like what this image protrayed, we keep a record of value:index in a hashmap. we iterate through the array, and once we find the second value, we are garrenteed to find the solution to the problem.