Compilare: user.cpp: In function ‘int main()’: user.cpp:139:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("robot2.out", "w", stdout); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:103:37: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,SIZE,1,input_file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:131:41: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,SIZE,1,input_file); ^