Deduplicate Events List (with Sorting + Map/Stack)

Deduplicate Events List You are given a list of events events. Each event contains: event_id: integer (can be negative or 0) timestamp: integer The list may be unsorted, and the same event_id may appear multiple times. Dedup rule: For each event_id, keep only the event with the largest (latest) timestamp and discard the rest. Return the deduplicated list sorted by (event_id ascending, timestamp ascending). Input (stdin) First line: integer n = number of events Next n lines: event_id timestamp Output (stdout) Print m lines (deduplicated events): event_id timestamp, sorted. Constraints 0 <= n <= 2e5 -1e9 <= event_id <= 1e9 -1e9 <= timestamp <= 1e9 Handle edge cases: n=0, negative/0 ids, many duplicates, unsorted input. Sample Tests See the Chinese section for 5 examples. Example Input 6 1 10 2 5 1 7 2 8 0 3 -1 4 Output -1 4 0 3 1 10 2 8