Add Unique Numbers in Sequence | Dataford Interview Questions

FSS payment-processing workflows may receive repeated numeric amounts within a sequence. Given a sequence of integers, return the sum of each distinct value exactly once.

The order of values does not affect the result. Negative numbers and zero must be handled normally. Aim for a single pass through the sequence using additional memory proportional to the number of distinct values.

Formal Specification

Implement sum_unique_amounts(amounts).

Input: amounts, a list of integers.
Output: An integer equal to the sum of all distinct integers in amounts.
If amounts is empty, return 0.

Constraints

0 <= len(amounts) <= 10^5
-10^9 <= amounts[i] <= 10^9
Each input value is an integer
The result fits within Python's integer range

Function Signature

def sum_unique_amounts(amounts):

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