Description
1. Two Sum

Given an array of integers nums and an integer target, returnindices 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 thesame element twice.

You can return the answer in any order.

Example 1:

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

Example 2:

Input: nums = [3,2,4], target = 6 
Output: [1,2]
Explanation: Because nums[1] + nums[2] == 6, we return [1, 2].

Example 3:

Input: nums = [3,3], target = 6 
Output: [0,1]
Constraints:
  • 2 <= nums.length <= 104
  • -109 <= nums[i] <= 109
  • -109 <= target <= 109
  • Only one valid answer exists.
Testcases

Case 1
Case 2
Case 3

Input:

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

Output:

[0,1]