Compilare: user.cpp: In function ‘int main()’: user.cpp:108:20: warning: variable ‘startval’ set but not used [-Wunused-but-set-variable] int k,ok=0,startval=0,nr0=0; ^ user.cpp:104:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("unlock.out","w",stdout); ^ user.cpp: In constructor ‘InputReader::InputReader(const char*)’: user.cpp:38:48: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, BUFFER_SIZE, 1, file); ^ user.cpp: In member function ‘void InputReader::advance()’: user.cpp:70:52: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, BUFFER_SIZE, 1, file); ^