Is there any limit to the length of the string after which hashing should be avoided. Also can the hashing solutions be easily hacked in contests ?
№ | Пользователь | Рейтинг |
---|---|---|
1 | tourist | 3690 |
2 | jiangly | 3647 |
3 | Benq | 3581 |
4 | orzdevinwang | 3570 |
5 | Geothermal | 3569 |
5 | cnnfls_csy | 3569 |
7 | Radewoosh | 3509 |
8 | ecnerwala | 3486 |
9 | jqdai0815 | 3474 |
10 | gyh20 | 3447 |
Страны | Города | Организации | Всё → |
№ | Пользователь | Вклад |
---|---|---|
1 | maomao90 | 174 |
2 | awoo | 164 |
3 | adamant | 163 |
4 | TheScrasse | 159 |
5 | nor | 157 |
6 | maroonrk | 155 |
7 | -is-this-fft- | 152 |
8 | Petr | 146 |
8 | orz | 146 |
10 | BledDest | 145 |
Название |
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According to the birthday paradox, if m = 1e9 + 9, we can random about 200000 strings and the possibility of collisions is more than 99.9999%!
Simple code can calculate the possibility:
Also, if you want to make your hashing become hard to hack, there are two possible choice:
use a long long prime as m
use two or more hash functions
Sorry for my poor English, I hope this can help you:)
Well, that might make it a bit harder to hack, but still hackable. You should also make your base randomized.