Compilare: user.cpp: In function ‘int main()’: user.cpp:27: warning: operation on ‘k’ may be undefined user.cpp:8: warning: unused variable ‘sf’ user.cpp:14: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:18: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result