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
- QUERY a b : ask for the maximum edge cost on the path from node a to node b
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.
For each "QUERY" operation, write one integer representing its result.
Input: 1 3 1 2 1 2 3 2 QUERY 1 2 CHANGE 1 3 QUERY 1 2 DONE Output: 1 3
See this as well.
if you get TLE, just optimize function max, dfs & hld decomposition like this guy : https://ideone.com/Ykg63S
Dont know why, but when i used HLD with implicit LCA got TLE, but when I used the LCA got AC.
Ignore the comments. Just don't use cin/cout. Nice problem to start HLD.Last edit: 2019-09-13 09:12:40
I am getting RTE in java even with inputs.
AC'd with a lot of debugging. SPOJ toolkit recommended.
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.
This is crazy. In the end I made optimizations like
yes there is no issue with struct my code is also working...i have implemented lca,hld and segtree using struct
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
|Added by:||Thanh-Vy Hua|
|Cluster:||Cube (Intel G860)|
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