Compilare: user.cpp: In function ‘int main()’: user.cpp:54: warning: operation on ‘X’ may be undefined user.cpp:60: warning: operation on ‘X’ may be undefined user.cpp:70: warning: operation on ‘X’ may be undefined user.cpp:76: warning: operation on ‘X’ may be undefined user.cpp:21: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:22: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:48: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:64: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:67: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result