Hello!
Given a binary tree, find a** maximum path for each node**.
Hope to get an optimal solution Input- N=6
edges= 1->2,2->3,1->4,4->5,4->6
output= 2 3 4 3 4 4
Thanks in advance!
№ | 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 | 172 |
2 | adamant | 164 |
3 | awoo | 163 |
4 | TheScrasse | 160 |
5 | nor | 157 |
6 | maroonrk | 155 |
7 | -is-this-fft- | 152 |
8 | Petr | 146 |
9 | orz | 145 |
9 | pajenegod | 145 |
Hello!
Given a binary tree, find a** maximum path for each node**.
Hope to get an optimal solution Input- N=6
edges= 1->2,2->3,1->4,4->5,4->6
output= 2 3 4 3 4 4
Thanks in advance!
Название |
---|
You can solve this problem using DP on trees, check this tutorial
solition in O(n log n)
lets find the answer for node V. V has O(logN) nodes in path from V to root. Let U — node in this path. then also let's find for each V max_d[V] — max len from V to some node in subtree of V.
let's try to update the answer for V. there's a exactly one son of U, who is in the path from V to root, let it be Z. then there's the algorithm to find the ans for V, if U is known.
i think it's pretty obvious why it works. so then whole alg is this: