checkin.cpp: In function 'bool isOk(int)': checkin.cpp:15: error: 'greater' is not a member of 'std' checkin.cpp:15: error: expected primary-expression before 'int' checkin.cpp: In function 'int main()': checkin.cpp:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result checkin.cpp:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result checkin.cpp:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result checkin.cpp:42: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result checkin.cpp:43: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result