Compilare: user.cpp: In function ‘void afis(std::string)’: user.cpp:9: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:83: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:84: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:134: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:137: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result