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Comments
+1

1st and 3rd part must have the same length x
0

Maybe that's the reason why he's still gray.
+9

I print nothing and got WA at first...
0

An edge from u to v doesn't mean that u is the parent of v if we build the tree from root 1
0

There's a template function in c++17 names "std::data", which makes your data variable ambiguous
0

OMG... I tried to calculate the MIN danger, which should be 2^(n — v) where v is the vertices number of the max complete sub-graph, which is NP... it bordered me so long since I find that it's just a misunderstanding when reading this....