1. tmp = L;
while(tmp->next !=p) tmp=tmp->next;
tmp->next = s;
s->next = p;
2. tmp = L;
while(tmp->next != null ) tmp=tmp->next;
tmp->next =s;
s->next =null;
3. tmp = p->next;
p->next = tmp->next;
4. tmp = L->next;
L->next = tmp->next;
1. tmp = L;
while(tmp->next !=p) tmp=tmp->next;
tmp->next = s;
s->next = p;
2. tmp = L;
while(tmp->next != null ) tmp=tmp->next;
tmp->next =s;
s->next =null;
3. tmp = p->next;
p->next = tmp->next;
4. tmp = L->next;
L->next = tmp->next;