QTREE2 - Query on a tree II
You are given a tree (an undirected acyclic connected graph) with N nodes, and edges numbered 1, 2, 3 ...N-1. Each edge has an integer value assigned to it, representing its length.
We will ask you to perform some instructions of the following form:
- DIST a b : ask for the distance between node a and node b
or - KTH a b k : ask for the k-th node on the path from node a to node b
Example:
N = 6
1 2 1 // edge connects node 1 and node 2 has cost 1
2 4 1
2 5 2
1 3 1
3 6 2
Path from node 4 to node 6 is 4 → 2 → 1 → 3 → 6
DIST 4 6 : answer is 5 (1 + 1 + 1 + 2 = 5)
KTH 4 6 4 : answer is 3 (the 4-th node on the path from node 4 to node 6 is 3)
Input
The first line of input contains an integer t, the number of test cases (t <= 25). t test cases follow.
For each test case:
- In the first line there is an integer N (N <= 10000)
- In the next N-1 lines, the i-th line describes the i-th edge: a line with three integers a b c denotes an edge between a, b of cost c (c <= 100000)
- The next lines contain instructions "DIST a b" or "KTH a b k"
- The end of each test case is signified by the string "DONE".
There is one blank line between successive tests.
Output
For each "DIST" or "KTH" operation, write one integer representing its result.
Print one blank line after each test.
Example
Input: 1 6 1 2 1 2 4 1 2 5 2 1 3 1 3 6 2 DIST 4 6 KTH 4 6 4 DONE Output: 5 3
hide comments
moss3011:
2016-05-15 09:32:36
getting tle may be bcoz of method of finding ancestors ...plz help
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sigma_poet225:
2016-04-03 03:22:29
Get Wa and Don't know why. |
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Abhinandan Agarwal:
2016-03-26 14:13:56
@chandan Mittal- No, I checked it. Last edit: 2016-03-26 14:35:26 |
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latte0119:
2015-10-22 11:03:20
I was using doubling algorithm to get lca.
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paimon:
2015-06-26 17:59:44
beware test cases "DIST a a" and "KTH a a 1" Last edit: 2015-06-26 18:00:27 |
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Luis Manuel D�az Bar�n:
2014-10-12 21:27:20
I was using a LCA algorithm with NlogN preprocess and O(1) query and received rte, I changed it to NlogN preprocess and logN query... now I received TLE, wdf is wrong with this problem? Finding the Kth ancestor ran in O(N) for the worst case. Help Please. My Mail:
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zengshiyuan:
2014-10-02 10:48:37
Easy problem.Can use heavy-light decomposition
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Chandan Mittal:
2014-07-18 20:25:02
can there be a case when k is greater than number of nodes between a and b, both inclusive? |
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Mojtaba FayazBakhsh:
2013-08-21 17:05:54
got AC using 32 bit integer |
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Parit Agarwal:
2013-07-16 07:52:46
getting SIGSEGV ....
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Added by: | Thanh-Vy Hua |
Date: | 2006-08-27 |
Time limit: | 1s |
Source limit: | 15000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | All except: ERL JS-RHINO NODEJS PERL6 VB.NET |
Resource: | Special thanks to Ivan Krasilnikov for his alternative solution |