Compilare: user.cpp: In function ‘bool check(long int, long int)’: user.cpp:29:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<list[id].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:83:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<G.size();i++){ ^ user.cpp:69:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("teroristi2.in","r",stdin); ^ user.cpp:70:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("teroristi2.out","w",stdout); ^ user.cpp:72:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld %ld",&n,&m,&mod); ^ user.cpp:74:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld%ld",&x,&y); ^