Compilare: user.cpp: In function ‘int main()’: user.cpp:93: warning: comparison between signed and unsigned integer expressions user.cpp:104: warning: comparison between signed and unsigned integer expressions user.cpp:128: warning: name lookup of ‘i’ changed user.cpp:117: warning: matches this ‘i’ under ISO standard rules user.cpp:124: warning: matches this ‘i’ under old rules user.cpp:114: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result