Sum sales by category
A shop's daily sales feed stores one line item per row as "category,amount", where amount is an integer that may be negative (a refund). Build the mini pivot the manager sees each evening: a dictionary mapping each category to the sum of its amounts. Example: ["toys,20", "games,15", "toys,5"] gives {"toys": 25, "games": 15}.
Implement
category_totals(rows: list[str]) → dict[str,int]Examples
in
[["toys,20","games,15","toys,5"]]out{"toys":25,"games":15}What a strong answer looks like
State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
0:00 of about 10 min
solution.py
InputExpectedGot
[["toys,20","games,15","toys,5"]]{"toys":25,"games":15}not run yetsample