简单的最小生成树

import java.util.Scanner;

/**
 * @author ddd
 * @create 2020-03-11    16:49
 **/
public class MinTree {
    private  static int INF=99999999;
    private  static int N=100;
    private  static boolean[] s=new boolean[N];
    private  static int[] closest=new int[N];
    private  static int[] lowcost=new int[N];
    private static void Prim(int n,int u0,int c[][]) {
        s[u0] = true;
        int i, j;
        for (i = 1; i <= n; i++) {
            if (i != u0) {
                lowcost[i] = c[u0][i];
                closest[i] = u0;
                s[i]=false;
            }
            else {
                s[i]=true;
                lowcost[i] = 0;
            }
        }
        for (i = 1; i <= n; i++) {
            int temp=INF;
            int t = u0;
            for (j = 1; j <= n; j++) {
                if ((!s[j]) && (lowcost[j] < temp)) {
                    t = j;
                    temp = lowcost[j];
                }
            }
            if (t == u0) {
                break;
            }
            s[t] = true;
            for (j = 1; j <= n; j++) {
                if ((!s[j]) && (c[t][j] < lowcost[j])) {

                    lowcost[j] = c[t][j];
                    closest[j] = t;

                }
            }
        }
    }


    public static void main(String[] args) {
        int n,m,u,v,w;
        int[][] c=new int[N][N];
//        System.out.println("请输入节点数n和边数m");
        Scanner scanner=new Scanner(System.in);
        n=scanner.nextInt();
        m=scanner.nextInt();
        int u0=scanner.nextInt();
        int sumcost=0;
        for(int i=0;i<=n;i++){
            for(int j=0;j<=n;j++){
                c[i][j]=INF;
            }
        }
 //       System.out.println("输入节点数U，V和边值W");
        for(int i=1;i<=m;i++){
            u=scanner.nextInt();
            v=scanner.nextInt();
            w=scanner.nextInt();
            c[u][v]=w;
            c[v][u]=w;
        }
//        for(int i=1;i<=n;i++){
//            for(int j=1;j<=n;j++){
//                System.out.println("c[i][j] = " + c[i][j]);
//            }
//        }
//        System.out.println("输入任意一节点u0");
//        u0=scanner.nextInt();
        Prim(n,u0,c);
        int max=0;
        for(int i=1;i<=n;i++){
            sumcost+=lowcost[i];
            if(max<=lowcost[i]){
                max=lowcost[i];
            }
        }
        System.out.println(sumcost);
    }
}