Compilare: user.cpp: In function ‘int main()’: user.cpp:23:8: warning: unused variable ‘i’ [-Wunused-variable] int n,i = 0; ^ user.cpp:27:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(input,"%d",&n); ^ user.cpp:29:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(input,"%ld %ld",&a,&b); ^