Compilare: user.cpp: In function ‘int main()’: user.cpp:30:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<V.size();j++) ^ user.cpp:23:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colaj.in","r",stdin); ^ user.cpp:24:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("colaj.out","w",stdout); ^ user.cpp:25:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&K,&M,&N); ^ user.cpp:29:96: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&Rect.first.second,&Rect.first.first,&Rect.second.second,&Rect.second.first); ^