Aggregate Error Codes by Timestamp

Problem

Given a list of log lines logs and a list of target error codes target_codes, write a function that parses each line and returns a mapping from timestamp to error-code counts. Each valid log line has the format TIMESTAMP|LEVEL|CODE|MESSAGE. Only count lines whose CODE is in target_codes. Ignore malformed lines.

Constraints

• 1 <= len(logs) <= 10^5
• 1 <= len(target_codes) <= 10^3
• Each log line is a string of length 1 to 10^4
• Valid lines contain exactly 4 fields separated by |
• Return timestamps in the order they first appear in valid matching lines