Compilare: user.cpp: In function ‘int main()’: user.cpp:13: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:14: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:17: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result /tmp/ccSYXy1U.o: In function `main': user.cpp:(.text+0x56): warning: the `gets' function is dangerous and should not be used.