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| class Solution {
public Node copyRandomList(Node head) {
if (head == null) {
return null;
}
Map<Node, Node> oldToNewMap = new IdentityHashMap<>();
Node node = head;
while (node != null) {
oldToNewMap.put(node, new Node(node.val));
node = node.next;
}
for (Map.Entry<Node, Node> entry : oldToNewMap.entrySet()) {
Node old = entry.getKey(), duplicate = entry.getValue();
duplicate.next = oldToNewMap.get(old.next);
duplicate.random = oldToNewMap.get(old.random);
}
return oldToNewMap.get(head);
}
}
|
Linked List
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| class Solution {
public Node copyRandomList(Node head) {
if (head == null) {
return null;
}
Node curr = head;
while (curr != null) {
Node duplicate = new Node(curr.val);
Node next = curr.next;
curr.next = duplicate;
duplicate.next = next;
curr = next;
}
curr = head;
while (curr != null) {
Node duplicate = curr.next;
if (curr.random != null) {
duplicate.random = curr.random.next;
}
curr = duplicate.next;
}
Node duplicateHead = head.next;
curr = head;
while (curr != null) {
Node duplicate = curr.next;
Node next = duplicate.next;
curr.next = next;
if (next != null) {
duplicate.next = next.next;
}
curr = next;
}
return duplicateHead;
}
}
|
References
138. Copy List with Random Pointer
剑指 Offer 35. 复杂链表的复制