https://leetcode-cn.com/problems/min-cost-to-connect-all-points/

分析

模板題。

#define P pair<int, int>
#define PI pair<int, P>
class Solution {
public:
    vector<PI> V;
    int fa[1010]={0};
    int find(int n)
    {
        return fa[n]==n?n:fa[n]=find(fa[n]);
    }
    int minCostConnectPoints(vector<vector<int>>& points) {
        int m=points.size();
        for(int i=0;i<m;i++)fa[i]=i;
        for(int i=0;i<m;i++)
        {
            int x1=points[i][0],y1=points[i][1];
            for(int j=i+1;j<m;j++)
            {
                int x2=points[j][0],y2=points[j][1];
                V.push_back(PI(abs(x1-x2)+abs(y1-y2),P(i,j)));
            }
        }
        sort(V.begin(),V.end());
        int ans=0;
        for(auto x:V)
        {
            int dist=x.first,node1=x.second.first,node2=x.second.second;
            if(find(node1)!=find(node2))
            {
                ans+=dist;
                fa[find(node1)]=find(node2);
            }
        }
        return ans;
    }
};