QTREE - Query on a tree
You are given a tree (an acyclic undirected connected graph) with N nodes, and edges numbered 1, 2, 3...N-1.
We will ask you to perfrom some instructions of the following form:
- CHANGE i ti : change the cost of the i-th edge to ti
or - QUERY a b : ask for the maximum edge cost on the path from node a to node b
Input
The first line of input contains an integer t, the number of test cases (t <= 20). 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 <= 1000000),
- The next lines contain instructions "CHANGE i ti" or "QUERY a b",
- The end of each test case is signified by the string "DONE".
There is one blank line between successive tests.
Output
For each "QUERY" operation, write one integer representing its result.
Example
Input: 1 3 1 2 1 2 3 2 QUERY 1 2 CHANGE 1 3 QUERY 1 2 DONE Output: 1 3
hide comments
naimsantos:
2019-11-24 18:58:55
Dont know why, but when i used HLD with implicit LCA got TLE, but when I used the LCA got AC. |
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peregrine:
2019-09-12 08:47:13
Ignore the comments. Just don't use cin/cout. Nice problem to start HLD. Last edit: 2019-09-13 09:12:40 |
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umang696:
2019-09-09 13:19:14
I am getting RTE in java even with inputs.
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quachtridat:
2019-08-29 22:11:49
AC'd with a lot of debugging. SPOJ toolkit recommended.
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omar_alhelo:
2019-08-10 19:37:58
If you're still getting TLE or RTE with c++, make sure to return 0 in main and use void return type with corresponding functions. |
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kshubham02:
2019-07-12 02:58:50
This is crazy. In the end I made optimizations like
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coldbeer:
2019-07-02 20:01:34
yes there is no issue with struct my code is also working...i have implemented lca,hld and segtree using struct |
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armoking:
2019-06-13 15:20:04
Well, there is all OK with c++ struct - I have 0.33 sec AC. There are no negative weights. For query like (a, a), I have answer 0. So - it is good standard task. Author, thank you! Last edit: 2019-06-13 15:22:23 |
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Md. Abdulla Al Mamun (Nayon):
2019-06-04 10:09:19
c++11 features support, max function used AC in 0.29s |
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malviyanshiv:
2019-02-08 17:33:51
I was forced to use scanf and printf... |
Added by: | Thanh-Vy Hua |
Date: | 2005-06-08 |
Time limit: | 1s |
Source limit: | 15000B |
Memory limit: | 1536MB |
Cluster: | Cube (Intel G860) |
Languages: | ADA95 ASM32 BASH BF C CSHARP CPP CLPS LISP sbcl LISP clisp D FORTRAN HASK ICON ICK JAVA LUA NEM NICE OCAML PAS-GPC PAS-FPC PERL PHP PIKE PRLG-swi PYTHON RUBY SCM guile SCM qobi ST TEXT WHITESPACE |