Compilare: user.cpp: In function ‘int main()’: user.cpp:36:10: warning: variable ‘a’ set but not used [-Wunused-but-set-variable] char a; ^ user.cpp:35:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(si,"%i",&n); ^ user.cpp:40:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(v,105,si); ^