For the 566D - Реструктуризация компании

Basic Disjoint Set C++ implementation (w/o ranks) using int vector

class DisjointSet{ public:

    vector<int> parent;

    DisjointSet(int n): parent(n) { for(int i=0; i<n; i++) parent[i] = i; }

    void join(int a, int b) { parent[find(b)] = find(a); }

    int find(int a){ return a == parent[a] ? a : parent[a] = find(parent[a]); }

    bool check(int a, int b){ return find(a) == find(b); }
};