1 public class DisjoinSet
2 {
3
4 public static void main(String[] args)
5 {
6 DisjoinSet disjoin = new DisjoinSet(8);
7
8 disjoin.union(4, 3);
9 disjoin.union(5, 4);
10 disjoin.union(6, 5);
11 disjoin.union(7, 6);
12 disjoin.union(8, 7);
13
14 int c = disjoin.find(3);
15 disjoin.display();
16 }
17
18
19 private int n;
20
21 private int[] parents;
22
23 private int[] rank;
24
25
26 public DisjoinSet(int n)
27 {
28 this.n = n;
29 init();
30 }
31
32 private void init()
33 {
34 parents = new int[n + 1];
35 rank = new int[n + 1];
36
37 for (int i = 1; i <= n; i++) {
38 parents[i] = i;
39 rank[i] = i;
40 }
41 }
42
43 public int find(int x)
44 {
45 int parent = x;
46 while (parent != parents[parent]) {
47 parent = parents[parent];
48 }
49
50 disjoin(x, parent);
51 return parent;
52 }
53
54 private void disjoin(int x, int parent)
55 {
56 int temp;
57 while (x != parent) {
58 temp = parents[x];
59 parents[x] = parent;
60 x = temp;
61 }
62 }
63
64 public void union(int a, int b)
65 {
66 int compare = compare(rank[a], rank[b]);
67 if (compare == 1) {
68 parents[b] = a;
69 }
70 else {
71 parents[a] = b;
72 }
73 }
74
75 private int compare(int a, int b)
76 {
77 return a > b ? 1 : a < b ? -1 : 0;
78 }
79
80 public void display()
81 {
82 for (int i : rank) {
83 System.out.print(" " + i + " ");
84 }
85
86 System.out.println();
87
88 for (int i : parents) {
89 System.out.print(" " + i + " ");
90 }
91 }
92 }
