集成并查集

class dsu {
    public:
    vector<int> fa ;
    int n ;
    dsu(int _n) : n(_n){
        fa.resize(n);
        iota(fa.begin() ,fa.end() , 0);
    }
    inline int get(int x){
        if(x != fa[x])return fa[x] = get(fa[x]);
        else return x;
    }
    inline bool unite(int x , int y ){
        x = get(x);
        y = get(y);
        if(x == y)return 0 ;
        else {
            fa[x] = y ;
            return 1;
        }
 
    }
};