LeetCode: Copy List with Random Pointer

跟clone graph思路一样

/**
 * Definition for singly-linked list with a random pointer.
 * struct RandomListNode {
 *     int label;
 *     RandomListNode *next, *random;
 *     RandomListNode(int x) : label(x), next(NULL), random(NULL) {}
 * };
 */
class Solution {
public:
    RandomListNode *copyRandomList(RandomListNode *head) {
        // IMPORTANT: Please reset any member data you declared, as
        // the same Solution instance will be reused for each test case.
        if (head == NULL) return NULL;
        map<RandomListNode*, RandomListNode*> S;
        RandomListNode *res = new RandomListNode(head->label);
        S[head] = res;
        queue<RandomListNode *> que;
        que.push(head);
        while (!que.empty()) {
            RandomListNode *top = que.front();
            que.pop();
            if (top->next) {
                RandomListNode *next = new RandomListNode(top->next->label);
                S[top->next] = next;
                S[top]->next = next;
                que.push(top->next);
            }
            if (top->random) {
                RandomListNode *tmp = top->random;
                if (S.count(tmp)) S[top]->random = S[tmp];
                else {
                    RandomListNode *random = new RandomListNode(tmp->label);
                    S[tmp] = random;
                    S[top]->random = random;
                }
            }
        }
        return res;
    }
};

 C#

/**
 * Definition for singly-linked list with a random pointer.
 * public class RandomListNode {
 *     public int label;
 *     public RandomListNode next, random;
 *     public RandomListNode(int x) { this.label = x; }
 * };
 */
public class Solution {
    public RandomListNode CopyRandomList(RandomListNode head) {
        if (head == null) return null;
        Dictionary<RandomListNode, RandomListNode> S = new Dictionary<RandomListNode, RandomListNode>();
        RandomListNode ans = new RandomListNode(head.label);
        S.Add(head, ans);
        Queue<RandomListNode> que = new Queue<RandomListNode>();
        que.Enqueue(head);
        while (que.Count != 0) {
            RandomListNode peek = que.Peek();
            que.Dequeue();
            if (peek.next != null) {
                RandomListNode next = new RandomListNode(peek.next.label);
                if (S.ContainsKey(peek.next)) S[peek.next] = next;
                else S.Add(peek.next, next);
                S[peek].next = next;
                que.Enqueue(peek.next);
            }
            if (peek.random != null) {
                RandomListNode tmp = peek.random;
                if (S.ContainsKey(tmp)) S[peek].random = S[tmp];
                else {
                    RandomListNode random = new RandomListNode(tmp.label);
                    S[tmp] = random;
                    S[peek].random = random;
                }
            }
        }
        return ans;
    }
}