string.cpp: In function 'int main()': string.cpp:25: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result string.cpp:26: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result string.cpp:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result string.cpp:29: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccMVYa5G.o: In function `main': string.cpp:(.text+0x10a): warning: the `gets' function is dangerous and should not be used.