<p>You are given an array <code>points</code> representing integer coordinates of some points on a 2D-plane, where <code>points[i] = [x<sub>i</sub>, y<sub>i</sub>]</code>.</p>

<p>The cost of connecting two points <code>[x<sub>i</sub>, y<sub>i</sub>]</code> and <code>[x<sub>j</sub>, y<sub>j</sub>]</code> is the <strong>manhattan distance</strong> between them: <code>|x<sub>i</sub> - x<sub>j</sub>| + |y<sub>i</sub> - y<sub>j</sub>|</code>, where <code>|val|</code> denotes the absolute value of <code>val</code>.</p>

<p>Return <em>the minimum cost to make all points connected.</em> All points are connected if there is <strong>exactly one</strong> simple path between any two points.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://assets.leetcode.com/uploads/2020/08/26/d.png" style="width: 214px; height: 268px;" />
<pre>
<strong>Input:</strong> points = [[0,0],[2,2],[3,10],[5,2],[7,0]]
<strong>Output:</strong> 20
<strong>Explanation:</strong> 
<img alt="" src="https://assets.leetcode.com/uploads/2020/08/26/c.png" style="width: 214px; height: 268px;" />
We can connect the points as shown above to get the minimum cost of 20.
Notice that there is a unique path between every pair of points.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> points = [[3,12],[-2,5],[-4,1]]
<strong>Output:</strong> 18
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= points.length &lt;= 1000</code></li>
	<li><code>-10<sup>6</sup> &lt;= x<sub>i</sub>, y<sub>i</sub> &lt;= 10<sup>6</sup></code></li>
	<li>All pairs <code>(x<sub>i</sub>, y<sub>i</sub>)</code> are distinct.</li>
</ul>

class Solution {
public:
    struct Edge {
    int x, y, w;
};

int parent[1001];
int Size[1001];
void makeSet(int n){
    for(int i =0;i<n;i++){
        parent[i] = i;
        Size[i] =1;
    }
}


int Find(int x){
    if(parent[x] == x) return x;
    return parent[x] = Find(parent[x]);
}

bool Union(int a, int b){
    a = Find(a);
    b = Find(b);
    if(a == b) return false;
    if(Size[a] < Size[b]) swap(a,b);
    Size[a] += Size[b]; parent[b] = a;
    return true;
}
static bool cmp(Edge a, Edge b){
    return a.w < b.w;
}
int kruskal(vector<Edge>& edge, int n){
    int res =0;
    int edgeUsed = 0;
    makeSet(n);
    sort(edge.begin(), edge.end(), cmp);
    for(int i =0; i< edge.size();i++){
        if(edgeUsed == n - 1) break;

        if(Union(edge[i].x, edge[i].y)){;
            res+=edge[i].w;
            edgeUsed++;
        }
    }
    return res;
}

int dis(vector<int> a, vector<int> b){
    return abs(a[0] - b[0]) + abs(a[1] - b[1]);
}
int minCostConnectPoints(vector<vector<int>> &points) {
    vector<Edge> edgeList;
    for (int i = 0; i < points.size()-1; i++) {
        for(int j = i+1; j<points.size(); j++){
            edgeList.push_back({i,j,dis(points[i], points[j])});
        }
    }
    return kruskal(edgeList,points.size());

}
};
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