Compilare: user.cpp: In function ‘void BFS(int)’: user.cpp:25:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[k].size();i++) ^ user.cpp:18:13: warning: unused variable ‘n1’ [-Wunused-variable] int k,l,n1=n*n; ^ user.cpp: In function ‘int main()’: user.cpp:56:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<v[i].size()-1;k++) ^ user.cpp:63:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<v[j].size()-1;k++) ^