Compilare: user.cpp: In function ‘int main()’: user.cpp:12: warning: comparison between signed and unsigned integer expressions user.cpp:17: warning: comparison between signed and unsigned integer expressions user.cpp:19: warning: comparison between signed and unsigned integer expressions user.cpp:6: warning: unused variable ‘i’ user.cpp:6: warning: unused variable ‘j’ user.cpp:10: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result