Project Euler 107：Minimal network 最小网络

package Level4;
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.TreeMap;


public class PE0107{
    static int[][] network = new int[40][40];
    static int len = 40;
    static int AllSum=0;
    static int shortestSum =0;
    public static void run(){
        String filename = "src/Level4/p107_network.txt";
        readData(filename);
        AllSum = getArrSum();
        System.out.println("所有元素的和："+AllSum);
        shortestSum = Prim();
        System.out.println("最短路径的和："+shortestSum);
        System.out.println("路径之差："+ (AllSum - shortestSum));
    }
    public static int Prim(){
        ArrayList<Integer> known = new ArrayList<Integer>();
        ArrayList<Integer> goods = new ArrayList<Integer>();
        TreeMap<Integer, Integer> map = new TreeMap<Integer, Integer>();
        known.add(0);
        map.put(0, 0);
        while(true){
            int min = Integer.MAX_VALUE;
            int index = -1;
            int mapindex = -1;
            for(int i=0;i<known.size();i++){
                for(int j=0;j< len;j++){
                    int now = network[map.get(i)][j];
                    if(now < min && now!=-1 && !known.contains(j)){
                        min = now;
                        index = j;
                        mapindex = known.size();
                    }
                }
            }
            goods.add(min);
            known.add(index);
            map.put(mapindex,index);
            if( known.size() == len)
                break;
        }
        int sum =0;
        for(int i=0;i<goods.size() ;i++){
            sum+=goods.get(i);
        }
        return sum;
    }
    public static int getArrSum(){
        int sum = 0;
        for(int i=0;i<network.length;i++){
            for(int j=i+1;j<network[0].length;j++){
                if(network[i][j]!=-1)
                    sum +=network[i][j];
            }
        }
        return sum;
    }
    public static void StrToArr(int index,String line){
        String[] strArr = line.split(",");
        
        for(int i=0;i<strArr.length;i++){
            if(!strArr[i].equals("-")){
                network[index][i] = Integer.parseInt(strArr[i]);
            }else{
                network[index][i] = -1;
            }
        }
    } 
    public static void readData(String filename){
        BufferedReader bufferedReader;
        int index = 0;
        try {
            bufferedReader = new BufferedReader(new FileReader(filename));
            String line ="";
            try {
                while((line = bufferedReader.readLine())!=null){
                    StrToArr(index,line);
                    index++;
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                System.out.println("文件没有数据");
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            System.out.println("没有发现文件");
        }
    }
    public static void main(String[] args){
        long t0 = System.currentTimeMillis();
        run();
        long t1 = System.currentTimeMillis();
        long t = t1 - t0;
        System.out.println("running time="+t/1000+"s"+t%1000+"ms");
    }
}