很简单的链表找环

进入debug的时候有bug，实在找不到，求助大家

1.Node.java

1. package Chapter2;
   
2. 
   
3. public class Node<T> {
   
4. public T data;
   
5. public Node<T> next;
   
6. public Node(T d, Node<T> n){
   
7. data = d;
   
8. next = n;
   
9. }
   
10. }

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2.MylinkedList.java

1. package Chapter2;
   
2. 
   
3. //Singly Linked List
   
4. public class MyLinkedList<T> {
   
5. public Node<T> head;
   
6. 
   
7. public MyLinkedList(Node<T> h) {
   
8. head = h;
   
9. }
   
10. public MyLinkedList() {
    
11. head = null;
    
12. }
    
13. 
    
14. public MyLinkedList(T[] dataArray) {
    
15. if (dataArray == null || dataArray.length <= 0)
    
16. return;
    
17. head = new Node<>(dataArray[0], null);
    
18. Node<T> node = head;
    
19. for (int i = 1; i < dataArray.length; i++) {
    
20. node.next = new Node<T>(dataArray[i], null);
    
21. node = node.next;
    
22. }
    
23. }
    
24. 
    
25. public void print() {
    
26. Node<T> cur = head;
    
27. while (cur != null) {
    
28. System.out.print(cur.data);
    
29. if (cur.next != null) {
    
30. System.out.print(" -> ");
    
31. }
    
32. cur = cur.next;
    
33. }
    
34. System.out.println();
    
35. }
    
36. 
    
37. public void prepend(T data) {
    
38. Node<T> next = head != null ? head.next : null;
    
39. head = new Node<T>(data, next);
    
40. }
    
41. 
    
42. public MyLinkedList<T> reverse() {
    
43. if(head == null) return null;
    
44. Node<T> newHead = head;
    
45. Node<T> cur = head.next;
    
46. head.next = null;
    
47. while(cur != null) {
    
48. Node<T> next = cur.next;
    
49. cur.next = newHead;
    
50. newHead = cur;
    
51. cur = next;
    
52. }
    
53. head = newHead;
    
54. return this;
    
55. }
    
56. }

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3.findbegning.java

1. package Chapter2;
   
2. 
   
3. public class findBeginning{
   
4. 
   
5. public static<T> Node<T> findBegining(MyLinkedList<T> list){
   
6. 
   
7. if(list.head==null||list==null)
   
8. 
   
9. return null;
   
10. 
    
11. Node<T> fast=list.head;
    
12. Node<T> slow=list.head;
    
13. 
    
14. while(fast!=null&&fast.next!=null){
    
15. slow=slow.next;
    
16. fast=fast.next.next;
    
17. 
    
18. if(slow==fast) {break;
    
19. }
    
20. 
    
21. if(fast ==null|| fast.next==null){
    
22. return null ;
    
23. 
    
24. 
    
25. }
    
26. }
    
27. slow=list.head;
    
28. while(slow!=fast){
    
29. slow=slow.next;
    
30. fast=fast.next;
    
31. 
    
32. }
    
33. 
    
34. return fast;
    
35. }
    
36. 
    
37. public static void main(String[] args){
    
38. 
    
39. MyLinkedList<Integer> list=new MyLinkedList<>(new Integer[] {1,2,3,4,5,3});
    
40. 
    
41. list.print();
    
42. System.out.println(findBegining(list).data);
    
43. 
    
44. 
    
45. }
    
46. 
    
47. }

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编译没错误，运行有错，求解答，加大米

MyLinkedList<Integer> list=new MyLinkedList<>(new Integer[] {1,2,3,4,5,3});

我认为这个链表没有环

smzfeng 发表于 2014-9-26 08:18
MyLinkedList list=new MyLinkedList(new Integer[] {1,2,3,4,5,3});

我认为这个链表没有环

是的，我自己写testcase很少，没注意。。。