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Triplet - MarisaOJ: Marisa Online Judge

Triplet

Time limit: 1000 ms
Memory limit: 256 MB
For a tree with $n$ vertices, let $d(u, v)$ be the number of edges on the simple path from $u$ to $v$. Given $q$ queries of the form $(a, b, c)$, find a vertex $x$ such that $d(a, x) + d(b, x) + d(c, x)$ is minimized. ### Input - The first line consists of two integers $n, q$. - The next $n - 1$ lines, each line contains three integers $u, v$, indicating an edge between $u$ and $v$. - The next $q$ lines, each line contains three integers $a, b, c$, a query. ### Output - For each query, print the vertex that satisfies the condition. ### Constraints - $1 \le n, q \le 10^5$. - $1 \le a, b, c \le n$. ### Sample test Input ``` 10 7 1 2 1 3 2 4 3 5 2 6 5 7 1 8 4 9 4 10 4 4 2 1 5 8 10 6 9 7 2 5 7 9 2 7 5 4 8 3 4 ``` Output: ``` 4 1 4 5 2 5 1 ```
Lowest common ancestor (LCA)
LCA
Distance query
Robot on tree
Heaviest edge
Equal path
Triplet
Path update
Second best minimum spanning tree
Oggy and the cockroaches
Topic
Tree
Data structure
Rating 1500
Solution (0) Solution