Compilare: user.cpp: In function ‘int main()’: user.cpp:172: warning: comparison between signed and unsigned integer expressions user.cpp:152: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:153: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:154: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:171: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result /tmp/cc7RFMNk.o: In function `main': user.cpp:(.text+0x73d): warning: the `gets' function is dangerous and should not be used.