Compilare: user.cpp: In function ‘int main()’: user.cpp:123:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("br.in","r",stdin); ^ user.cpp:124:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("br.out","w",stdout); ^ user.cpp: In member function ‘char InParser::read_ch()’: user.cpp:13:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, 4096, fin); ^