Compilare: user.cpp: In function ‘int main()’: user.cpp:99: warning: comparison between signed and unsigned integer expressions user.cpp:103: warning: suggest explicit braces to avoid ambiguous ‘else’ user.cpp:68: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:69: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result