Two-Sum Variant | Dataford Interview Questions

An Instacart pricing tool receives a list of integer item values and a target total. Return the indices of two distinct values whose sum equals the target.

You may assume that every valid input contains exactly one solution. Return the indices in increasing order, and do not use the same list element twice. If the list contains duplicate values, each occurrence may be used separately.

Formal Specification

Implement two_sum(nums, target).

Input: nums, a list of integers, and target, an integer.
Output: A list containing the two zero-based indices [i, j], where i < j and nums[i] + nums[j] == target.
The input list must not be modified.

Constraints

2 <= len(nums) <= 100,000
-10^9 <= nums[i] <= 10^9
-10^9 <= target <= 10^9
Exactly one valid pair exists
The same element cannot be used twice

Function Signature

def two_sum(nums, target):

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