Compilare: user.cpp: In function ‘bool BellmanFord(int)’: user.cpp:23:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[nod].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:38:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.in","r",stdin); ^ user.cpp:39:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.out","w",stdout); ^ user.cpp:40:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:43:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&x,&y,&c); ^