题解 | #单词缩写#

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

class Edge{
private int from;
private int to;
private int weight;
public Edge(){

}
public Edge(int from, int to, int weight) {
    this.from = from;
    this.to = to;
    this.weight = weight;
}
public int getFrom() {
    return from;
}

public void setFrom(int from) {
    this.from = from;
}

public int getTo() {
    return to;
}

public void setTo(int to) {
    this.to = to;
}

public int getWeight() {
    return weight;
}

public void setWeight(int weight) {
    this.weight = weight;
}

}

public class Main {
private static ArrayList<edge> edges = new ArrayList<>();
private static int destination = 0;
private static ArrayList<integer> distanceList = new ArrayList<>();</integer></edge>

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    String[] strArr = in.nextLine().split(" ");
    destination = Integer.parseInt(strArr[0]);
    int n = Integer.parseInt(strArr[1]);
    for(int i=0; i<n; i++){
        String[] strArr1 = in.nextLine().split(" ");
        Edge edge = new Edge(Integer.parseInt(strArr1[0]), Integer.parseInt(strArr1[1]), Integer.parseInt(strArr1[2]));
        edges.add(edge);
    }
    Edge edgestart = new Edge();
    int distancestart = 0;
    for(int i=0; i<edges.size(); i++){
        if(edges.get(i).getFrom()==0){
            edgestart = new Edge(edges.get(i).getFrom(), edges.get(i).getTo(), edges.get(i).getWeight());
            distancestart = edges.get(i).getWeight();
            break;
        }
    }
    getNext(edgestart, distancestart);

    if(distanceList.size()==0){
        System.out.println("-1");
    }
    else{
        System.out.println(Collections.min(distanceList));
    }

}




public static void getNext(Edge edge, int distance){
    if( edge.getTo()==destination ){
        distanceList.add(Integer.valueOf(distance));
    }
    else{
        for(int i=0; i<edges.size(); i++){
            if(edge.getTo() == edges.get(i).getFrom()){
                distance += edges.get(i).getWeight();
                getNext(edges.get(i), distance);
            }
        }
    }
}

}