Compilare: user.cpp: In function ‘int main()’: user.cpp:56:17: warning: suggest parentheses around ‘+’ inside ‘<<’ [-Wparentheses] if (1<<k+1 <= i) k++; ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:12:42: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,SIZE,1,input_file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:37:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,SIZE,1,input_file); ^