Copy List with Random Pointer

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

Return a deep copy of the list.

RandomListNode* result;
if (!head) return result;

// copy each node in the original list
RandomListNode* move = head;
while (move) {
RandomListNode* temp = new RandomListNode(move->label);
temp->next = move->next;
move->next = temp;
move = move->next->next;
}

// specify the random pointer of each new node
move = head;
while (move) {
if (move->random)
move->next->random = move->random->next;
move = move->next->next;
}

// break the list into two and return the new one
move = head;
RandomListNode* newHead = head->next;
RandomListNode* moveNew = newHead;
while (move) {
move->next = move->next ? move->next->next : NULL;
moveNew->next = moveNew->next ? moveNew->next->next : NULL;
move = move->next;
moveNew = moveNew->next;
}

return newHead;