Compilare: user.cpp: In function ‘int main()’: user.cpp:61: warning: operation on ‘Co’ may be undefined user.cpp:63: warning: operation on ‘Co’ may be undefined user.cpp:28: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result