Compilare: user.cpp: In function ‘int main()’: user.cpp:197: warning: comparison between signed and unsigned integer expressions user.cpp:154: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:155: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:156: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:161: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result