5151
5252<!-- 这里可写通用的实现逻辑 -->
5353
54+ 首先，遍历链表，完成对每个旧节点的复制。
55+
56+ ``` bash
57+ A -> B -> C -> D -> null
58+
59+ =>
60+
61+ A -> A1 -> B -> B1 -> C -> C1 -> D -> D1 -> null
62+ ```
63+
64+ 接着设置新节点的 ramdom 指针。
65+
66+ 然后遍历链表，修改旧节点和新节点的指向，将旧节点指向下一个旧节点，而新节点指向下一个新节点。
67+
68+ 最后返回第一个新节点即可。
69+
5470<!-- tabs:start -->
5571
5672### ** Python3**
@@ -66,23 +82,31 @@ class Node:
6682 self.next = next
6783 self.random = random
6884"""
85+
6986class Solution :
7087 def copyRandomList (self head : ' Node' ' Node'
71- if not head:
88+ if head is None :
7289 return None
73- copy_head = Node(- 1 )
74- cur, t = copy_head, head
75- cache = {}
76- while t:
77- cur.next = Node(t.val)
78- cache[t] = cur.next
79- cur, t = cur.next, t.next
80- t, cur = head, copy_head.next
81- while t:
82- cur.random = cache.get(t.random)
83- cur, t = cur.next, t.next
84- return copy_head.next
8590
91+ cur = head
92+ while cur:
93+ node = Node(cur.val, cur.next)
94+ cur.next = node
95+ cur = node.next
96+
97+ cur = head
98+ while cur:
99+ cur.next.random = None if cur.random is None else cur.random.next
100+ cur = cur.next.next
101+
102+ copy = head.next
103+ cur = head
104+ while cur:
105+ next = cur.next
106+ cur.next = next .next
107+ next .next = None if next .next is None else next .next.next
108+ cur = cur.next
109+ return copy
86110```
87111
88112### ** Java**
@@ -104,29 +128,139 @@ class Node {
104128 }
105129}
106130*/
131+
107132class Solution {
108133 public Node copyRandomList (Node head ) {
109134 if (head == null ) {
110135 return null ;
111136 }
112- Map<Node , Node > map = new HashMap<> ();
113- Node copyHead = new Node (- 1 );
114- Node cur = copyHead, t = head;
115- while (t != null ) {
116- Node node = new Node (t. val);
117- map. put(t, node);
137+
138+ Node cur = head;
139+ while (cur != null ) {
140+ Node node = new Node (cur. val);
141+ node. next = cur. next;
118142 cur. next = node;
119- cur = node;
120- t = t. next;
143+ cur = node. next;
121144 }
122- cur = copyHead. next;
123- while (head != null ) {
124- cur. random = map. get(head. random);
145+
146+ cur = head;
147+ while (cur != null ) {
148+ cur. next. random = cur. random == null ? null : cur. random. next;
149+ cur = cur. next. next;
150+ }
151+
152+ Node copy = head. next;
153+ cur = head;
154+ while (cur != null ) {
155+ Node next = cur. next;
156+ cur. next = next. next;
157+ next. next = next. next == null ? null : next. next. next;
125158 cur = cur. next;
126- head = head. next;
127159 }
128- return copyHead. next;
160+ return copy;
161+ }
162+ }
163+ ```
164+
165+ ### ** C++**
166+
167+ ``` cpp
168+ /*
169+ // Definition for a Node.
170+ class Node {
171+ public:
172+ int val;
173+ Node* next;
174+ Node* random;
175+
176+ Node(int _val) {
177+ val = _val;
178+ next = NULL;
179+ random = NULL;
180+ }
181+ };
182+ */
183+
184+ class Solution {
185+ public:
186+ Node* copyRandomList(Node* head) {
187+ if (!head) {
188+ return nullptr;
189+ }
190+ Node* cur = head;
191+ while (cur) {
192+ Node* node = new Node(cur->val);
193+ node->next = cur->next;
194+ cur->next = node;
195+ cur = node->next;
196+ }
197+
198+ cur = head;
199+ while (cur) {
200+ cur->next->random = cur->random ? cur->random->next : nullptr;
201+ cur = cur->next->next;
202+ }
203+
204+ Node* copy = head->next;
205+ cur = head;
206+ while (cur) {
207+ Node* next = cur->next;
208+ cur->next = next->next;
209+ next->next = next->next ? next->next->next : nullptr;
210+ cur = cur->next;
211+ }
212+ return copy;
213+ }
214+ };
215+ ```
216+
217+ ### ** C#**
218+
219+ ``` cs
220+ /*
221+ // Definition for a Node.
222+ public class Node {
223+ public int val;
224+ public Node next;
225+ public Node random;
226+
227+ public Node(int _val) {
228+ val = _val;
229+ next = null;
230+ random = null;
231+ }
232+ }
233+ */
234+
235+ public class Solution {
236+ public Node CopyRandomList (Node head ) {
237+ if (head == null ) {
238+ return null ;
239+ }
240+
241+ Node cur = head ;
242+ while (cur != null ) {
243+ Node node = new Node (cur .val );
244+ node .next = cur .next ;
245+ cur .next = node ;
246+ cur = node .next ;
247+ }
129248
249+ cur = head ;
250+ while (cur != null ) {
251+ cur .next .random = cur .random == null ? null : cur .random .next ;
252+ cur = cur .next .next ;
253+ }
254+
255+ Node copy = head .next ;
256+ cur = head ;
257+ while (cur != null ) {
258+ Node next = cur .next ;
259+ cur .next = next .next ;
260+ next .next = next .next == null ? null : next .next .next ;
261+ cur = cur .next ;
262+ }
263+ return copy ;
130264 }
131265}
132266```
@@ -142,96 +276,94 @@ class Solution {
142276 * this.random = random;
143277 * };
144278 */
279+
145280/**
146281 * @param {Node} head
147282 * @return {Node}
148283 */
149- var copyRandomList = function (head ) {
150- function copy (node ) {
151- if (! node) return null ;
152- if (isRead .get (node)) return isRead .get (node);
153- let newNode = new Node (node .val );
154- isRead .set (node, newNode);
155- newNode .random = copy (node .random );
156- newNode .next = copy (node .next );
157- return newNode;
158- }
159- let isRead = new Map ();
160- return copy (head);
284+ var copyRandomList = function (head ) {
285+ if (head == null ) {
286+ return null ;
287+ }
288+ let cur = head;
289+ while (cur != null ) {
290+ let node = new Node (cur .val , cur .next );
291+ cur .next = node;
292+ cur = node .next ;
293+ }
294+
295+ cur = head;
296+ while (cur != null ) {
297+ cur .next .random = cur .random == null ? null : cur .random .next ;
298+ cur = cur .next .next ;
299+ }
300+
301+ let copy = head .next ;
302+ cur = head;
303+ while (cur != null ) {
304+ let next = cur .next ;
305+ cur .next = next .next ;
306+ next .next = next .next == null ? null : next .next .next ;
307+ cur = cur .next ;
308+ }
309+ return copy;
161310};
162311```
163312
164313### ** Go**
165314
166315``` go
316+ /* *
317+ * Definition for a Node.
318+ * type Node struct {
319+ * Val int
320+ * Next *Node
321+ * Random *Node
322+ * }
323+ */
324+
167325func copyRandomList (head *Node ) *Node {
168326 if head == nil {
169327 return nil
170328 }
171- cur , next := head,head
172- // 完成对当前节点的复制
329+
330+ cur := head
173331 for cur != nil {
174- next = cur.Next
175- cur.Next = &Node{
332+ node := &Node{
176333 Val: cur.Val ,
177- Next: next ,
334+ Next: cur. Next ,
178335 Random: nil ,
179336 }
180- cur = next
337+ cur.Next = node
338+ cur = node.Next
181339 }
182- // 设置复制节点的random节点
340+
183341 cur = head
184- curCopy := head
185342 for cur != nil {
186- next = cur.Next .Next
187- curCopy = cur.Next
188343 if cur.Random == nil {
189- curCopy .Random = nil
344+ cur. Next .Random = nil
190345 } else {
191- curCopy .Random = cur.Random .Next
346+ cur. Next .Random = cur.Random .Next
192347 }
193- cur = next
348+ cur = cur. Next . Next
194349 }
195- res := head.Next
350+
351+ copy := head.Next
196352 cur = head
197353 for cur != nil {
198- next = cur.Next .Next
199- curCopy = cur.Next
200- cur.Next = next
201- if next != nil {
202- curCopy.Next = next.Next
354+ next := cur.Next
355+ cur.Next = next.Next
356+ if (next.Next == nil ) {
357+ next.Next = nil
203358 } else {
204- curCopy .Next = nil
359+ next .Next = next. Next . Next
205360 }
206361 cur = cur.Next
207362 }
208- return res
363+ return copy
209364}
210365```
211366
212- ### ** C++**
213-
214- ``` cpp
215- class Solution {
216- public:
217- Node* copyRandomList(Node* head) {
218- unordered_map<Node* , Node* > m;
219- Node* p = head;
220- while (p) {
221- m[ p] = new Node(p->val);
222- p = p->next;
223- }
224- p = head;
225- while (p) {
226- m[ p] ->next = m[ p->next] ;
227- m[ p] ->random = m[ p->random] ;
228- p = p->next;
229- }
230- return m[ head] ;
231- }
232- };
233- ```
234-
235367### ** ...**
236368
237369```
0 commit comments