1 import java.util.HashSet;
2 import java.util.Set;
3
4 public class Main {
5
6 // 从无序链表中删除重复项
7 public Node removeDup(Node node) {
8
9 if (node == null || node.next == null || node.next.next == null) {
10 return node;
11 }
12
13 Set<Integer> set = new HashSet<Integer>();
14
15 Node pre = node;
16 Node curr = node.next;
17
18 while (curr != null) {
19 if (set.contains(curr.data)) {
20 pre.next = curr.next;
21 } else {
22 set.add(curr.data);
23 pre = curr;
24 }
25
26 curr = curr.next;
27 }
28
29 return node;
30 }
31
32 public Node createListNodes() {
33 Node node7 = new Node(7, null);
34 Node node6 = new Node(5, node7);
35 Node node5 = new Node(4, node6);
36 Node node4 = new Node(5, node5);
37 Node node3 = new Node(1, node4);
38 Node node2 = new Node(3, node3);
39 Node node1 = new Node(1, node2);
40 Node head = new Node(0, node1); // head pointer
41
42 return head;
43 }
44
45 public static void main(String[] args) {
46 Main main = new Main();
47 Node node = main.removeDup(main.createListNodes());
48
49 if (node != null) {
50 node = node.next;
51 while (node != null) {
52 System.out.println(node.data);
53 node = node.next;
54 }
55 }
56 }
57 }
