Compilare: user.cpp: In function ‘void Lee(long int, long int)’: user.cpp:50:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=1;i<poss.size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:59:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("go.in","r",stdin); ^ user.cpp:60:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("go.out","w",stdout); ^ user.cpp:62:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&m); ^ user.cpp:65:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&id[i][j]); ^