bacan.cpp: In function 'int main()': bacan.cpp:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result bacan.cpp:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result bacan.cpp:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result bacan.cpp:38: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccn0zVAu.o: In function `main': bacan.cpp:(.text+0x105): warning: the `gets' function is dangerous and should not be used.