Compilare: user.c: In function ‘back’: user.c:25:11: warning: unused variable ‘c’ [-Wunused-variable] int i,c=1,ok; ^ user.c: In function ‘main’: user.c:47:15: warning: variable ‘pg’ set but not used [-Wunused-but-set-variable] FILE *pf,*pg; ^ user.c:52:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(pf,"%d %d",&n,&s); ^ user.c:55:15: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(pf,"%d",&v[i]); ^