Compilare: user.cpp: In function ‘bool DFS(int)’: user.cpp:30:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[s].size();++i) if(v[s][i] != viz[s]) ^ user.cpp: In function ‘void DFS2(int, int)’: user.cpp:62:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[s].size();++i) if(!viz[v[s][i]]) ^ user.cpp: In function ‘int main()’: user.cpp:73:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,a,b; ^