| № | Пользователь | Рейтинг |
|---|---|---|
| 1 | tourist | 4009 |
| 2 | jiangly | 3831 |
| 3 | Radewoosh | 3646 |
| 4 | jqdai0815 | 3620 |
| 4 | Benq | 3620 |
| 6 | orzdevinwang | 3529 |
| 7 | ecnerwala | 3446 |
| 8 | Um_nik | 3396 |
| 9 | gamegame | 3386 |
| 10 | ksun48 | 3373 |
| Страны | Города | Организации | Всё → |
| № | Пользователь | Вклад |
|---|---|---|
| 1 | cry | 164 |
| 1 | maomao90 | 164 |
| 3 | Um_nik | 163 |
| 4 | atcoder_official | 160 |
| 5 | -is-this-fft- | 158 |
| 6 | awoo | 157 |
| 7 | adamant | 156 |
| 8 | TheScrasse | 154 |
| 8 | nor | 154 |
| 10 | Dominater069 | 153 |
Hi !
I am trying to answer problem 155 at ACM.SGU.RU site .
My algortihm is sort by a[i] elements , then create a BST by k[i] elements.
I know my algorithm in worse case is O(n^2) and n can be 50000 ! So my answer get TLE .
What can I do for this problem ? Is my algorithm wrong or can be optimize ?
Cartesian tree is a well-known data structure, that can be created in O(N). You can read about it here.
Just to note, O(N) cartesian-tree building algorithm requires points to be sorted by x-coordinate beforehand. If that's not the case, this task is clearly no easier than general sorting problem, so the best time we can achieve is O(N log N).
i accept this problem via segment tree(its so hard to code for me) but one of my friend have a very very creative solution and i think his solution is near to your solution but you must change your approach to optimize your algorithm! sorry for my bad english!