Compilare: user.cpp: In function ‘void Union(const int&, const int&, std::vector<int>&)’: user.cpp:53:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(parent[i]==parent[v2] && i!=v2) parent[i]=parent[v1]; ^ user.cpp:61:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(parent[i]==parent[v1] && i!=v1) parent[i]=parent[v2]; ^ user.cpp: In function ‘int main()’: user.cpp:105:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<kruskal.size();i++) fout<<kruskal[i]<<'\n'; ^ user.cpp:70:12: warning: unused variable ‘j’ [-Wunused-variable] int N,M,i,j,costTotal=0,m=0; ^