考察点：链表
public RandomListNode copyRandomList(RandomListNode head) { if (head == null) return null; RandomListNode p = head; // copy every node and insert to list while (p != null) { RandomListNode copy = new RandomListNode(p.label); copy.next = p.next; p.next = copy; p = copy.next; } // copy random pointer for each new node p = head; while (p != null) { if (p.random != null) p.next.random = p.random.next; p = p.next.next; } // break list to two p = head; RandomListNode newHead = head.next; while (p != null) { RandomListNode temp = p.next; p.next = temp.next; if (temp.next != null) temp.next = temp.next.next; p = p.next; } return newHead;}
