Compilare: user.cpp: In function ‘void r(int&)’: user.cpp:29:37: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(f,1,MAX,stdin),p=0; ^ user.cpp:35:37: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(f,1,MAX,stdin),p=0; ^ user.cpp: In function ‘int main()’: user.cpp:89:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hotel.in","r",stdin); ^ user.cpp:90:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hotel.out","w",stdout); ^ user.cpp:91:25: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(f,1,MAX,stdin); ^