Compilare: user.cpp: In function ‘int main()’: user.cpp:22: warning: comparison between signed and unsigned integer expressions user.cpp:24: warning: array subscript has type ‘char’ user.cpp:30: warning: array subscript has type ‘char’ user.cpp:14: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:15: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:19: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result