Compilare: user.cpp: In function ‘long long int optim(int, int, int, int)’: user.cpp:87:9: warning: unused variable ‘i’ [-Wunused-variable] int i, left = x; ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:18:43: 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:45:47: 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 function ‘void write()’: user.cpp:128:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("operatii.out", "w", stdout); ^