librerias/UnionFind.cpp at master · obalcells/librerias · GitHub

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#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long long int ll;

#include <bits/stdc++.h>

using namespace std;

typedef pair<int,int> ii;
typedef vector<int> vi;
typedef long long int ll;

class UnionFind {
private:
    vi p, rank;
    int n;
public:
	UnionFind(int N) {
		rank.assign(N, 0);
		p.assign(N, 0);
		for(int i = 0; i < N; ++i) p[i] = i;
        n = N;
	}

	int findSet(int i) { return (p[i] == i) ? i : (p[i] = findSet(p[i])); } //with path compression

	bool sameSet(int i, int j) { return (findSet(i) == findSet(j)); }

	void UnionSet(int i, int j) {
			if(!sameSet(i, j)) {
					int x = findSet(i), y = findSet(j);
					if(rank[x] > rank[y]) p[y] = x;
					else {
						p[x] = y;
						if(rank[x] == rank[y]) { rank[y]++; }
					}
			}
	}

    int countSets() {
        set<int> sets;
        for(int i = 0; i < n; ++i) {
            sets.insert(p[i]);
        }
        return (int)sets.size();
    }
};

int main() {

	return 0;
}