JZ25 复杂链表的复制

https://www.nowcoder.com/practice/f836b2c43afc4b35ad6adc41ec941dba

import java.util.HashMap;
/*
public class RandomListNode {
    int label;
    RandomListNode next = null;
    RandomListNode random = null;

    RandomListNode(int label) {
        this.label = label;
    }
}
*/
public class Solution {

    public RandomListNode Clone(RandomListNode pHead) {
        if (pHead == null) return null;

        HashMap<RandomListNode, RandomListNode> map = new HashMap<>();

        RandomListNode result = new RandomListNode(pHead.label);
        RandomListNode cur = pHead;
        RandomListNode p = result;

        while(pHead != null) {
            map.put(pHead, new RandomListNode(pHead.label));
            pHead = pHead.next;
        }

        // target作为新链表的头，由cur，p移动来复制链表
        while (cur != null) {
            p.next = map.get( cur.next );
            p.random = map.get( cur.random );

            cur = cur.next;
            p = p.next;
        }
        
        return result;
    }
    
}