📢 본 포스팅에 활용되는 기본 문제 및 자료 출처는 리트코드 Problems, https://leetcode.com/problemset/all/임을 밝힙니다. ✔ 문제 https://leetcode.com/problems/market-analysis-i/description/ Market Analysis I - LeetCode Can you solve this real interview question? Market Analysis I - Table: Users +----------------+---------+ | Column Name | Type | +----------------+---------+ | user_id | int | | join_date | date | | favorite_brand ..