class Solution {
private:
    vector<int> par, sz;
    
    int get_par(int x) {
        if (x != par[x])
            par[x] = get_par(par[x]);
        return par[x];
    }
    
    void join(int a, int b) {
        a = get_par(a), b = get_par(b);
        if (a != b) {
            if (sz[a] < sz[b]) swap(a, b);
            if (sz[a] == sz[b]) sz[a]++;
            
            par[b] = a;
        }
    }
    
public:
    int minCostConnectPoints(vector<vector<int>>& points) {
        int n = points.size();
        
        vector<vector<int>> dis;
        for (int i = 0; i < n; i++)
            for (int j = 0; j < n; j++)
                if (i != j) {
                    int res = abs(points[i][0] - points[j][0]) + abs(points[i][1] - points[j][1]);
                    vector<int> ext = {res, i, j};
                    dis.push_back(ext);
                }
        
        par = sz = vector<int>(n, 0);
        for (int i = 0; i < n; i++)
            par[i] = i;
        
        sort(begin(dis), end(dis));
        
        int ans = 0;
        for (auto x : dis) {
            int a = get_par(x[1]), b = get_par(x[2]);
            if (a != b) {
                join(x[1], x[2]);
                ans += x[0];
            }
        }
        
        return ans;
    }
};