Compilare: user.cpp: In function ‘int main()’: user.cpp:27: warning: suggest parentheses around ‘-’ inside ‘<<’ user.cpp:30: warning: format ‘%ld’ expects type ‘long int’, but argument 3 has type ‘int’ user.cpp:15: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:20: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result