Compilare: user.c: In function ‘main’: user.c:116:30: warning: variable ‘p2’ set but not used [-Wunused-but-set-variable] struct node *p1,*q1,*q2,*p2; q1=last[1]; p1=first[1]; ^ user.c:116:26: warning: variable ‘q2’ set but not used [-Wunused-but-set-variable] struct node *p1,*q1,*q2,*p2; q1=last[1]; p1=first[1]; ^ user.c:116:22: warning: variable ‘q1’ set but not used [-Wunused-but-set-variable] struct node *p1,*q1,*q2,*p2; q1=last[1]; p1=first[1]; ^ user.c:108:19: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] {fscanf(f,"%d",&x); ^