radio1.cpp: In function 'int main()': radio1.cpp:70: warning: comparison between signed and unsigned integer expressions radio1.cpp:92: warning: comparison between signed and unsigned integer expressions radio1.cpp:25: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result radio1.cpp:26: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result radio1.cpp:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result radio1.cpp:30: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result radio1.cpp:60: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/cceA3G3L.o: In function `main': radio1.cpp:(.text+0x102): warning: the `gets' function is dangerous and should not be used.