Two Sum Array Coding | Dataford Interview Questions

Your question is Two Sum Array Coding. Start with the requirements on the right.

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Problem

Iris software's developer tooling needs to identify a pair of positions in an integer sequence whose values match a requested total. Given an array nums and an integer target, return the indices of two distinct elements whose values add up to target.

You may assume that every valid input contains exactly one solution. The same array element cannot be used twice. Return the indices in ascending order of discovery, with the smaller index first.

Formal Specification

Input: nums, an array of integers, and target, an integer.
Output: An array [i, j] such that i < j and nums[i] + nums[j] == target.
If no pair exists, return an empty array, although valid test inputs guarantee a solution.

Constraints

2 <= nums.length <= 100,000
-10^9 <= nums[i] <= 10^9
-10^9 <= target <= 10^9
Exactly one valid pair exists for each graded input

Function Signature

def two_sum(nums, target):