DisjointSets

class Solution {
    int[] p;
    int[] r;
    int c = 0;
    public int countComponents1(int n, int[][] edges) {
        p = new int[n];
        r = new int[n];
        for (int i = 0; i < n; i++) {
            p[i] = i;
        }
        for (int[] edge: edges) {
            union(edge[0], edge[1]);
        }
        
        Set<Integer> set = new HashSet<>();
        for (int e: p)
            set.add(find(e));
        return set.size();
    }
    
    private int find(int x) {
        if (p[x] != x)
            p[x] = find(p[x]);
        return p[x];
    }
    
    private void union(int x, int y) {
        int fx = find(x);
        int fy = find(y);
        if (r[fx] < r[fy]) {
            p[fx] = fy;
        } else if (r[fx] > r[fy]) {
            p[fy] = fx;
        } else {
            p[fx] = fy;
            r[fx]++;
        }
     
    }
 }