Compilare: user.cpp: In function ‘int main()’: user.cpp:138:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xormites.out","w",stdout); ^ user.cpp: In constructor ‘Buffer::Buffer(std::string, int)’: user.cpp:20:50: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(name.c_str(), "r", stdin); ^ user.cpp: In member function ‘void Buffer::refill()’: user.cpp:62:43: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(&data[0], 1, dim, stdin); ^ user.cpp: In function ‘int guess()’: user.cpp:122:30: warning: ‘ones’ may be used uninitialized in this function [-Wmaybe-uninitialized] else ones++; ^