Compilare: user.cpp: In function ‘void read()’: user.cpp:18: warning: comparison between signed and unsigned integer expressions user.cpp:21: warning: array subscript has type ‘char’ user.cpp:23: warning: array subscript has type ‘char’ user.cpp: In function ‘int main()’: user.cpp:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result