Compilare: user.cpp: In function ‘int main()’: user.cpp:41:19: warning: variable ‘x’ set but not used [-Wunused-but-set-variable] int i,sum=0,n,x,y,j; ^ user.cpp:41:21: warning: variable ‘y’ set but not used [-Wunused-but-set-variable] int i,sum=0,n,x,y,j; ^ user.cpp:41:23: warning: unused variable ‘j’ [-Wunused-variable] int i,sum=0,n,x,y,j; ^ user.cpp:44:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^