Compilare: user.cpp: In function ‘void add(int)’: user.cpp:29:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<c.size();i++) ^ user.cpp: In function ‘void bfs()’: user.cpp:43:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<C.size();i++) ^ user.cpp: In function ‘void bfs2()’: user.cpp:67:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0;j<C[i]->P.size();j++) ^ user.cpp: In function ‘int main()’: user.cpp:86:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<s.size();i++) ^