Compilare: user.cpp: In function ‘void back(int)’: user.cpp:45: warning: name lookup of ‘j’ changed user.cpp:6: warning: matches this ‘j’ under ISO standard rules user.cpp:34: warning: matches this ‘j’ under old rules user.cpp:36: warning: suggest explicit braces to avoid ambiguous ‘else’ user.cpp: In function ‘int main()’: user.cpp:54: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:57: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result user.cpp:59: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result