can anyone give me any idea for this problem.
Problem: The Great Ball
| # | User | Rating |
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| 1 | Benq | 3792 |
| 2 | VivaciousAubergine | 3647 |
| 3 | Kevin114514 | 3611 |
| 4 | jiangly | 3583 |
| 5 | strapple | 3515 |
| 6 | tourist | 3470 |
| 7 | dXqwq | 3436 |
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| # | User | Contrib. |
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| 1 | Qingyu | 158 |
| 2 | adamant | 152 |
| 3 | Um_nik | 146 |
| 4 | Dominater069 | 144 |
| 5 | errorgorn | 141 |
| 6 | cry | 139 |
| 7 | Proof_by_QED | 136 |
| 8 | YuukiS | 135 |
| 9 | chromate00 | 134 |
| 9 | TheScrasse | 134 |
can anyone give me any idea for this problem.
Problem: The Great Ball
| Name |
|---|



Store each entrance and exit as an event (a change in number of people which is +1 or -1, and a time the event occurs). Then process the events in order of time and keep track of the number of people after each event.