agenda.cpp: In function 'int main()': agenda.cpp:26: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result agenda.cpp:27: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result agenda.cpp:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result /tmp/cccGbpCK.o: In function `main': agenda.cpp:(.text+0x8a0): warning: the `gets' function is dangerous and should not be used.