Two Sum

Given an array of integers nums of size n 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.

Note: The pair of integers must be in the order of their position in the array i.e., the smaller index first then comes the larger one.

Input Format

First Parameter - number n

Second Parameter - array of integers nums of size n

Third Parameter - number target

Output Format

Return the pair of indices in an array.

Example 1:

Input : 
   4
   2 7 11 15
   9
Output : 
    0 1
Explaination : nums[0] + nums[1] == 9, return 0, 1

Example 2:

Input : 
    3
    3 2 4
    6
Output : 
     1 2

Constraints:

• 2 <= N <= 10⁵
• -10⁹ <= arr[i] <= 10⁹
• -2 * 10⁹ <= target <= 2 * 10⁹
• Only one valid answer exists.
• Expected Time complexity: O(n)
• Expected Space complexity: O(1)