Compilare: user.cpp: In function ‘int df(int, int)’: user.cpp:21:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < neigh[node].size(); ++i) { ^ user.cpp:26:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:68:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size(); ++i) { ^