最小生成树Prim 模板

class Solution {
public:
    int mp[1005][1005] = {0};
    int cost[1005];
    int vis[1005] = {0};
    int sz;
    int prim(){
        int sum = 0;
        vis[0] = 1;
        for(int i = 0; i < sz - 1; i++){
            int _min = INT_MAX, sub_min;    
            //要将n-1个结点加入最小生成树
            for(int j = 1; j < sz; j ++){
                if(vis[j] == 0 && _min > cost[j]){
                    sub_min = j;
                    _min = cost[j];
                }
            }
            vis[sub_min] = 1;
            sum +=cost[sub_min];
            //更新最小生成树到其他节点的距离
            for(int j = 1; j < sz; j++){
                if(vis[j] == 0 && mp[sub_min][j] < cost[j]){
                    cost[j] = mp[sub_min][j];
                }
            }
        }
        return sum;
    }
    int minCostConnectPoints(vector<vector<int>>& points) {
        //初始化
        memset(mp, INT_MAX, sizeof(mp));
        sz = points.size();
        for(int i = 0; i < sz; i++){
            for(int j = i + 1; j < sz; j++){
                mp[i][j] = abs(points[i][0] - points[j][0]) + abs(points[i][1] - points[j][1]);
                mp[j][i] = mp[i][j];
            } 
        }
        cost[0] = 0;
        for(int i = 1; i < sz; i++){
            cost[i] = mp[0][i];
        }
        return prim();
    }
};