Copy List with Random Pointer

標籤：

1. Title

Copy List with Random Pointer

2. Http address

https://leetcode.com/problems/copy-list-with-random-pointer/

3. The question

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.

 4. My code(AC)

 

 1 class RandomListNode { 2     int label; 3     RandomListNode next,random; 4     public RandomListNode(int x) 5     { 6             this.label = x; 7     } 8  9 }10 11 //Accpeted12     public static RandomListNode copyRandomList(RandomListNode head)13     {14             Map<RandomListNode,RandomListNode> mapH = new HashMap<RandomListNode,RandomListNode>();15             RandomListNode re,    q,end;16             RandomListNode p = head;17             re = null;18             end = null;19             while( p != null )20             {21                 q = new RandomListNode(p.label);22                 if( end == null)23                 {24                     re = q;25                     end = q;26                 }else{27                     end.next = q;28                     end = q;29                 }30                 mapH.put(p,q);31                 p = p.next;32             }33 34             p = head;35             q = re;36             while( p != null && q != null) {37                 if( p.random != null )38                 {39                     q.random = mapH.get(p.random);40                 41                 }else{42                     q.random = null;43                 }44                 p = p.next;45                 q = q.next;46             }47         return re;48 49     }

 

 

Copy List with Random Pointer