Leetcode - Two Sum - Solution

Leetcode - Two Sum - Solution

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

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

You can return the answer in any order.

Example 1:

Input:

nums = [2,7,11,15], target = 9 
Output: [0,1] 
Output: Because nums[0] + nums[1] == 9, we return [0, 1].

Example 2:

Input:

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

Example 3:

Input:

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

Constraints:

  • 2 <= nums.length <= 103
  • -109 <= nums[i] <= 109
  • -109 <= target <= 109
  • Only one valid answer exists.

Solution in Python

class Solution:
    def twoSum(self, nums: List[int], target: int) -> List[int]:
        seen = {}
        for index,number in enumerate(nums):
            second_number = target-number
            if second_number in seen:
                return [seen[second_number], index]
            else:
                seen[number] = index

Subscribe to The Poor Coder | Algorithm Solutions

Don’t miss out on the latest issues. Sign up now to get access to the library of members-only issues.
[email protected]
Subscribe