Compilare: user.cpp: In function ‘int main()’: user.cpp:72:8: warning: variable ‘a’ set but not used [-Wunused-but-set-variable] ll a,b; ^ user.cpp:72:10: warning: variable ‘b’ set but not used [-Wunused-but-set-variable] ll a,b; ^ user.cpp:70:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&t); ^ user.cpp:75:38: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%lld %lld\n",&x,&y); ^