Compilare: user.cpp: In function ‘void BFF(long int)’: user.cpp:19:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<gOut[nod].size();i++){ ^ user.cpp: In function ‘void BFB(long int)’: user.cpp:28:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<gIn[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:59:30: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 2 has type ‘std::vector<std::vector<long int> >::size_type {aka unsigned int}’ [-Wformat=] printf("%ld\n",ans.size()); ^ user.cpp:60:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<ans.size();i++){ ^ user.cpp:61:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long j=0;j<ans[i].size();j++) ^ user.cpp:36:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:37:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp:39:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&m); ^ user.cpp:41:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&x,&y); ^