supertrees.cpp: In member function 'void DSU::init(int)':
supertrees.cpp:8:7: error: 'f2' was not declared in this scope
8 | f2(0,n,1)par[i]=i,sz[i]=1;
| ^~
supertrees.cpp: In function 'int construct(std::vector<std::vector<int> >)':
supertrees.cpp:29:16: error: 'd' was not declared in this scope
29 | if(d.root(i)==d.root(j))return 0;
| ^
supertrees.cpp:30:13: error: 'd' was not declared in this scope
30 | d.merge(u,v);
| ^
supertrees.cpp:30:21: error: 'u' was not declared in this scope
30 | d.merge(u,v);
| ^
supertrees.cpp:39:16: error: 'd' was not declared in this scope
39 | if(d.root(i)==d.root(j))return 0;
| ^