Leetcode - CopyWithRandomList
Algorithm: Iterate and copy the original list first. For the random pointer, just copy the value from the original list first. And use a map to store each node's old address and its corresponding new address. After the iteration, we can replace the value of the random pointer based on the map we get.
Mistakes I make:
(1) Beware when head == null.
(2) Forget during the iteration: node = node.next;
public class Solution { public RandomListNode copyRandomList(RandomListNode head) { if(head == null) return null; RandomListNode newHead = new RandomListNode(head.label); newHead.random = head.random; RandomListNode node = newHead; Map<RandomListNode,RandomListNode> addrRef = new HashMap<RandomListNode,RandomListNode>(); addrRef.put(head, node); head = head.next; while(head != null) { RandomListNode tnode = new RandomListNode(head.label); tnode.random = head.random; node.next = tnode; addrRef.put(head, tnode); head = head.next; node = tnode; } node = newHead; while(node != null) { node.random = addrRef.get(node.random); node = node.next; } return newHead; } }
【推荐】编程新体验,更懂你的AI,立即体验豆包MarsCode编程助手
【推荐】凌霞软件回馈社区,博客园 & 1Panel & Halo 联合会员上线
【推荐】抖音旗下AI助手豆包,你的智能百科全书,全免费不限次数
【推荐】博客园社区专享云产品让利特惠,阿里云新客6.5折上折
【推荐】轻量又高性能的 SSH 工具 IShell:AI 加持,快人一步