Identify Customers Visiting on Multiple Different Days

amazon Given a file with logs, each log contains a timestamp and a customer ID. Find the repeat customers who visited the website on multiple different days. Example input: log1: 2023-01-01,user1 log2: 2023-01-02,user2 log3: 2023-01-03,user1 log4: 2023-01-01,user3 log5: 2023-01-04,user2 Output: user1 user2 Implement a function to complete the task and provide sufficient test cases and data size. Example Input 2023-01-01,user1 2023-01-02,user2 2023-01-03,user1 2023-01-01,user3 2023-01-04,user2