head=0 p=head while p!=-1 k=p p=a[p][1] | head=0 p=head while a[p][1]!=-1: p=a[p][1] | head=0 p=head while a[a[p][1]][1]!=-1: p=a[p][1] | head=0 p=head n=len(a) while n>1: p=a[p][1] n-=1 |
A | B | C | D |