gray.cpp: In function 'void cit(int*)': gray.cpp:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result gray.cpp: In function 'int main()': gray.cpp:162: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result gray.cpp:163: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result gray.cpp:164: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result gray.cpp:169: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result gray.cpp:204: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result