leetcode 之Copy List with Random Pointer（23）

RandomListNode *randomList(RandomListNode *head)
{
//复制每个结点，并将新结点放在旧结点之后
for (RandomListNode *cur = head; cur != nullptr;)
{
RandomListNode *node = new RandomListNode(cur->label);
node->next = cur->next;
cur->next = node;
cur = node->next;
}

//修改新结点的Random指针
for (RandomListNode *cur = head; cur != nullptr;)
{
if (cur->random != nullptr)cur->next->random = cur->random->next;

cur = cur->next->next;
}

//将新旧链表断开
RandomListNode dummy(-1);
for (RandomListNode *cur = head,*new_cur=&dummy; cur != nullptr;)
{
new_cur->next = cur->next;
new_cur = new_cur->next;

cur->next = cur->next->next;
cur = cur->next;

}

return dummy.next;
}