Compilare: user.cpp: In function ‘int bellman(int)’: user.cpp:72:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<G[node].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:16:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.in","r",stdin); ^ user.cpp:17:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("lanterna.out","w",stdout); ^