Java航班图：正确计算并显示经停城市连接及其总距离

// HWDriverPrep.java

// ... 其他代码 ...

private static void showConnections(HWGraph g, Vertex layOverVertex) {
    String layoverCityLabel = layOverVertex.label;
    int distanceToLayover = layOverVertex.weight; // 从起始城市到经停城市的距离

    // 获取从经停城市出发的所有直接连接
    ArrayList<Vertex> connectionsFromLayover = g.getConnections(layoverCityLabel);

    System.out.printf("\n从经停城市 %s 出发的连接 (从起始城市到此距离: %d):\n",
                      layoverCityLabel, distanceToLayover);

    if (connectionsFromLayover != null && !connectionsFromLayover.isEmpty()) {
        for (Vertex connectedCity : connectionsFromLayover) {
            // 为每个连接调用重构后的 connect 方法
            connect(layoverCityLabel, connectedCity, distanceToLayover);
        }
    } else {
        System.out.println("未找到从 " + layoverCityLabel + " 出发的直接连接。");
    }
}

// ... 其他代码 ...

// HWDriverPrep.java

// ... 其他代码 ...

// 重构后的 connect 方法，用于显示单个连接及其总距离
private static void connect(String fromCity, Vertex toCity, int initialDistance) {
    int totalDistance = initialDistance + toCity.weight; // 计算总距离
    System.out.printf("%s -> %s (本段距离: %d), 从起始城市总距离: %d\n",
                      fromCity, toCity.label, toCity.weight, totalDistance);
}

// ... 其他代码 ...

// HWDriverPrep.java
import java.util.ArrayList;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

public class HWDriverPrep {
    public static void main(String[] args) {
        HWGraph g = createGraph();
        printGraph( g ); // 打印整个图的连接，用于调试或概览
        Set<String> keys = g.getKeys();
        String startCity = "Chicago";
        String layOver = getLayOverCity( keys, startCity); // 获取用户输入的经停城市

        // 获取从起始城市到经停城市的Vertex对象，其中包含了该段的距离
        Vertex v = g.getThisVertex( startCity, layOver); 

        if (v == null) {
            System.out.println("经停城市 " + layOver + " 未在从 " + startCity + " 出发的路径中找到。");
            return;
        }

        System.out.printf("\n从起始城市: %s 到经停城市: %s (距离: %d) 的连接如下:\n", 
                          startCity, v.label, v.weight);

        // 调用修改后的 showConnections 方法
        showConnections( g, v );
    }

    private static void printGraph(HWGraph g) {
        System.out.println("\n--- 完整航班图连接 ---");
        g.graphMap.forEach(
                (key,value) -> show(key,value));
        System.out.println("--------------------");
    }
    private static void show(String key, ArrayList<Vertex> value) {
        System.out.println("城市: " + key + " 的连接:");
        for(Vertex v : value){
            System.out.println("  -> " + v.label + " (距离: " + v.weight + ")");
        }
    }
    private static String getLayOverCity(Set<String> keys, String startCity) {
        Scanner s = new Scanner(System.in);
        String oStr = "";
        String cm = "";
        for(String item: keys)
        {
            oStr += cm + item;
            cm = ", ";
        }

        System.out.printf("\n请选择一个经停城市 (%s): ",oStr);
        String retItem = s.nextLine();
        return retItem;
    }

    // 修改后的 showConnections 方法
    private static void showConnections(HWGraph g, Vertex layOverVertex) {