Compilare: user.cpp: In function ‘int main()’: user.cpp:102: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long long int’ user.cpp:54: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:55: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:57: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result /tmp/ccIVKy5f.o: In function `main': user.cpp:(.text+0x460): warning: the `gets' function is dangerous and should not be used.