floyd算法：java-find the mincost route

package com.work5;

import java.io.PrintWriter;
import java.util.Scanner;


public class DemoE {
    static int max = 999999;
    static void floyd(int n,int mp[][],int dis[][]){
        int MinCost = max;
        for (int k = 1; k <= n; k++) {
            for (int i = 1; i < n; i++) {
                for (int j = i+1; j < k ; j++) {
                    MinCost = Math.min(MinCost,dis[i][j]+mp[i][k]+mp[k][j]);

                }
            }
            //更新dis
            for (int i = 1; i <= n; i++) {
                if (dis[i][k]<99999){
                    for (int j = 1; j <= n; j++) {
                        dis[i][j]=Math.min(dis[i][j],dis[i][k]+dis[k][j]);
                    }
                }
            }
        }
        if(MinCost>99999)
            System.out.println("It's impossible.");
        else
            System.out.println(MinCost);
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()){
            int N = sc.nextInt();//景区的个数
            int M = sc.nextInt();//道路的条数，接下来的行数
            int map [][] = new int[N+1][N+1];
            int distance [][] = new int[N+1][N+1];
            //初始化map
            for (int i = 0; i <= N; i++) {
                for (int j = 0; j <= N; j++) {
                    if (i==j){
                        map[i][j] = 0;
                    }else {
                        map[i][j] = max;
                    }
                }
            }
            for (int i = 0; i < M; i++) {
                int x = sc.nextInt();
                int y = sc.nextInt();
                int v = sc.nextInt();
                map[x][y] = v;
                map[y][x] = v;
                distance[x][y] = v;
                distance[y][x] = v;
            }
            floyd(N,map,distance);
        }
    }
}