Compilare: user.cpp: In function ‘int main()’: user.cpp:7:12: warning: unused variable ‘i’ [-Wunused-variable] int n, i, x; ^ user.cpp:7:15: warning: unused variable ‘x’ [-Wunused-variable] int n, i, x; ^ user.cpp:11:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d", &n); ^