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QTREE3 - Query on a tree again! |
English | Vietnamese |
You are given a tree (an acyclic undirected connected graph) with N nodes. The tree nodes are numbered from 1 to N. In the start, the color of any node in the tree is white.
We will ask you to perfrom some instructions of the following form:
- 0 i : change the color of the i-th node (from white to black, or from black to white);
or - 1 v : ask for the id of the first black node on the path from node 1 to node v. if it doesn't exist, you may return -1 as its result.
Input
In the first line there are two integers N and Q.
In the next N-1 lines describe the edges in the tree: a line with two integers a b denotes an edge between a and b.
The next Q lines contain instructions "0 i" or "1 v" (1 ≤ i, v ≤ N).
Output
For each "1 v" operation, write one integer representing its result.
Example
Input: 9 8 1 2 1 3 2 4 2 9 5 9 7 9 8 9 6 8 1 3 0 8 1 6 1 7 0 2 1 9 0 2 1 9 Output: -1 8 -1 2 -1
Constraints & Limits
There are 12 real input files.
For 1/3 of the test cases, N=5000, Q=400000.
For 1/3 of the test cases, N=10000, Q=300000.
For 1/3 of the test cases, N=100000, Q=100000.
Added by: | Fudan University Problem Setters |
Date: | 2008-06-14 |
Time limit: | 2s |
Source limit: | 50000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ERL JS-RHINO NODEJS PERL6 VB.NET |
Resource: | VNOI Marathon '08 - Round 6/DivA Problem Setter: Blue Mary |
hide comments
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2024-12-19 12:13:53
this easy segment problems should be removed from spoj instead you can think about this problems(sack) dsu on tree https://codeforces.com/blog/entry/44351 Last edit: 2024-12-19 12:14:19 |
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2024-04-24 18:55:52
why segment tree and hld not getting ac? |
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2024-04-10 16:30:43
<snip> where is problem [Simes]: this is not the place for debugging code, use the forum. Last edit: 2024-04-10 20:56:08 |
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2024-01-22 11:40:03
What does 0 and 41.57 mean in the judge status ? |
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2024-01-05 19:52:00
is there a solution without HLD? |
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2023-02-04 03:14:44
replying to llite_27 HLD, use sets to keep track of black nodes in heavy paths |
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2023-01-10 15:32:26
hmmm just ett and lazy segment |
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2022-08-17 11:51:44
my code using HLD +BIT +Binary Search <snip> Please share if you done using any other method thanks in advance... [Simes]: Read the footer - Don't post source code here, use the forum. Last edit: 2022-08-17 12:30:35 |
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2022-03-29 02:28:35
You don't need HLD. Just binary lifting and Euler tour are sufficient. Don't use HLD when you don't need to. |
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2022-01-06 17:22:02
Perfect score is 100 btw. Last edit: 2022-01-06 17:22:38 |