Compilare: user.c: In function ‘main’: user.c:30:19: warning: unused variable ‘j’ [-Wunused-variable] { int n,k,i,x,y,j; ^ user.c:30:17: warning: unused variable ‘y’ [-Wunused-variable] { int n,k,i,x,y,j; ^ user.c: In function ‘pop_front’: user.c:26:5: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.c: In function ‘main’: user.c:39:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d %d",&n,&k); ^ user.c:44:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&x); ^