hora.cpp: In function 'int main()': hora.cpp:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result hora.cpp:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result hora.cpp:13: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccRMOqhL.o: In function `main': hora.cpp:(.text+0x86): warning: the `gets' function is dangerous and should not be used.