Leetcode: Number of Connected Components in an Undirected Graph

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph.

Example 1:
     0          3
     |          |
     1 --- 2    4
Given n = 5 and edges = [[0, 1], [1, 2], [3, 4]], return 2.

Example 2:
     0           4
     |           |
     1 --- 2 --- 3
Given n = 5 and edges = [[0, 1], [1, 2], [2, 3], [3, 4]], return 1.

Note:
You can assume that no duplicate edges will appear in edges. Since all edges are undirected, [0, 1] is the same as [1, 0] and thus will not appear together in edges.

Use Union Find to figure out the number of connected components

public class Solution {
    public int countComponents(int n, int[][] edges) {
        unionFind uf = new unionFind(n);
        for (int[] edge : edges) {
            if (!uf.isConnected(edge[0], edge[1])) {
                uf.union(edge[0], edge[1]);
            }
        }
        return uf.findCount();
    }
    
    public class unionFind{
            int[] ids;
            int count;
            
            public unionFind(int num) {
                this.ids = new int[num];
                for (int i=0; i<num; i++) {
                    ids[i] = i;
                }
                this.count = num;
            }
            
            public int find(int i) {
                return ids[i];
            }
            
            public void union(int i1, int i2) {
                int id1 = find(i1);
                int id2 = find(i2);
                if (id1 != id2) {
                    for (int i=0; i<ids.length; i++) {
                        if (ids[i] == id2) {
                            ids[i] = id1;
                        }
                    }
                    count--;
                }
            }
            
            public boolean isConnected(int i1, int i2) {
                return find(i1)==find(i2);
            }
            
            public int findCount() {
                return count;
            }
        }
}