Compilare: user.cpp: In function ‘void BFS()’: user.cpp:21:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=1; i<v[k].size(); ++i) ^ user.cpp:25:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[k].size(); ++i) { ^ user.cpp:15:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,k,nr; ^ user.cpp: In function ‘int main()’: user.cpp:48:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[X].size(); ++i) { ^ user.cpp:56:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<sol.size(); ++i) ^