Compilare: user.cpp: In function ‘int bfs()’: user.cpp:57:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[virf].size() ; ++i){ ^ user.cpp: In function ‘void solve()’: user.cpp:107:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < sol.size() ; ++i) ^ user.cpp:115:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[ind].size() ; ++i) ^ user.cpp:117:55: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[sol[index].second].size() ; ++i) ^ user.cpp:122:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < sol.size() ; ++i) ^ user.cpp:104:9: warning: unused variable ‘sz_min’ [-Wunused-variable] int sz_min = sol.size() / 2; ^ user.cpp:117:40: warning: ‘index’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i = 0 ; i < v[sol[index].second].size() ; ++i) ^ user.cpp:115:41: warning: ‘ind’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i = 0 ; i < v[ind].size() ; ++i) ^