题目描述如上,先是没看懂题,看了样例,就是将输入的链表再输出,但是每个节点有random指针,由于不能确定节点的random所指的节点是否已知;
1.遍历链表里的节点,并存在hashmap中 2.再遍历一遍,调整map中节点的next、random指针 3.返回map /* // Definition for a Node. class Node { public: int val; Node* next; Node* random; Node(int _val) { val = _val; next = NULL; random = NULL; } }; */ class Solution { public: Node* copyRandomList(Node* head) { if(head == NULL) return NULL; Node *tmp = head; unordered_map<Node*, Node*>mp; while(tmp!=NULL){ mp[tmp] = new Node(tmp->val); tmp = tmp->next; } tmp = head; while(tmp!=NULL){ mp[tmp]->next = mp[tmp->next]; mp[tmp]->random = mp[tmp->random]; tmp = tmp->next; } return mp[head]; } };