Compilare: user.cpp: In function ‘void Desc(int)’: user.cpp:53:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘void Check(int)’: user.cpp:74:25: warning: left operand of comma operator has no effect [-Wunused-value] for(i = 1, j = 0; i <= n, j < k; i++) ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:15:47: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:37:51: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, SIZE, 1, input_file); ^