tests/LibraryChecker_Unionfind.test.cpp

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• Last update: 2026-11-04 14:46:41+09:00
• Problem: https://judge.yosupo.jp/problem/unionfind

Depends on

• union_find (DataStructure/union_find.hpp)

Code

#define PROBLEM "https://judge.yosupo.jp/problem/unionfind"

#include <bits/stdc++.h>
using namespace std;

#include "union_find.hpp"
    
int main() {
    int N, Q;
    cin >> N >> Q;
    UnionFind uf(N);
    for (int q = 0; q < Q; ++q) {
        int type, x, y;
        cin >> type >> x >> y;
        if (type == 0) uf.merge(x, y);
        else {
            if (uf.same(x, y)) cout << 1 << endl;
            else cout << 0 << endl;
        }
        //cout << uf << endl;
    }
}

#line 1 "tests/LibraryChecker_Unionfind.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/unionfind"

#include <bits/stdc++.h>
using namespace std;

#line 3 "DataStructure/union_find.hpp"
using namespace std;

// Union-Find
struct UnionFind {
    // core member
    vector<int> par, nex;

    // constructor
    UnionFind() { }
    UnionFind(int N) : par(N, -1), nex(N) {
        init(N);
    }
    void init(int N) {
        par.assign(N, -1);
        nex.resize(N);
        for (int i = 0; i < N; ++i) nex[i] = i;
    }
    
    // core methods
    int root(int x) {
        if (par[x] < 0) return x;
        else return par[x] = root(par[x]);
    }
    
    bool same(int x, int y) {
        return root(x) == root(y);
    }
    
    bool merge(int x, int y) {
        x = root(x), y = root(y);
        if (x == y) return false;
        if (par[x] > par[y]) swap(x, y); // merge technique
        par[x] += par[y];
        par[y] = x;
        swap(nex[x], nex[y]);
        return true;
    }
    
    int size(int x) {
        return -par[root(x)];
    }
    
    // get group
    vector<int> group(int x) {
        vector<int> res({x});
        while (nex[res.back()] != x) res.push_back(nex[res.back()]);
        return res;
    }
    vector<vector<int>> groups() {
        vector<vector<int>> member(par.size());
        for (int v = 0; v < (int)par.size(); ++v) {
            member[root(v)].push_back(v);
        }
        vector<vector<int>> res;
        for (int v = 0; v < (int)par.size(); ++v) {
            if (!member[v].empty()) res.push_back(member[v]);
        }
        return res;
    }
    
    // debug
    friend ostream& operator << (ostream &s, UnionFind uf) {
        const vector<vector<int>> &gs = uf.groups();
        for (const vector<int> &g : gs) {
            s << "group: ";
            for (int v : g) s << v << " ";
            s << endl;
        }
        return s;
    }
};
#line 7 "tests/LibraryChecker_Unionfind.test.cpp"
    
int main() {
    int N, Q;
    cin >> N >> Q;
    UnionFind uf(N);
    for (int q = 0; q < Q; ++q) {
        int type, x, y;
        cin >> type >> x >> y;
        if (type == 0) uf.merge(x, y);
        else {
            if (uf.same(x, y)) cout << 1 << endl;
            else cout << 0 << endl;
        }
        //cout << uf << endl;
    }
}

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