Compilare: user.cpp: In function ‘int canmark(int)’: user.cpp:37:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<G[nod].size();i++) ^ user.cpp:43:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0;j<G[G[nod][i]].size();j++) ^ user.cpp: In function ‘void bfs()’: user.cpp:60:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<G[nod].size();i++) ^ user.cpp: In function ‘void solve()’: user.cpp:81:9: warning: unused variable ‘i’ [-Wunused-variable] int i; ^