138. Copy List with Random Pointer

A linked list is given such this each node contains an additional random pointer which could point to all node in the list or null.

Return a deep copy of the list.

1Randomlistnode *copyrandomlist (Randomlistnode *head)2     {3Unordered_map<randomlistnode *, Randomlistnode *>Listmap;4Randomlistnode *dummy =NewRandomlistnode (0), *oldnode, *newnode, *R;5         6R =dummy;7          for(OldNode = head; OldNode! = NULL; oldNode = oldnode->next)8         {9NewNode =NewRandomlistnode (oldnode->label);TenListmap[oldnode] =NewNode; OneR->next =NewNode; AR =NewNode; -         } -          the          for(OldNode = head; OldNode! = NULL; oldNode = oldnode->next) -Listmap[oldnode]->random = listmap[oldnode->random]; -          -r = dummy->Next; + Delete dummy; -         returnR; +}

138. Copy List with Random Pointer