2024/5/10

package com.example.underground.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.activerecord.Model;
import java.io.Serializable;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.Accessors;

/**
 * <p>
 * 
 * </p>
 *
 * @author xu
 * @since 2024-04-04
 */
@Getter
@Setter
@Accessors(chain = true)
@TableName("line")
@ApiModel(value = "Line对象", description = "")
public class Line extends Model<Line> {

    @TableId(value = "LineNumber", type = IdType.AUTO)
    private Integer lineNumber;

    @TableField("LineName")
    private String lineName;

    @Override
    public Serializable pkVal() {
        return this.lineNumber;
    }
}

package com.example.underground.entity;

import lombok.Data;

/**
 * 功能：
 * 作者：
 * 日期： 2024/4/9 15:49
 */
@Data
public class PreandNextstation {
    private String lineName;
    private String preStation;
    private String thisStation;
    private String nextStation;
}

package com.example.underground.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.activerecord.Model;
import java.io.Serializable;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.experimental.Accessors;

/**
 * <p>
 * 
 * </p>
 *
 * @author xu
 * @since 2024-04-04
 */
@Getter
@Setter
@Accessors(chain = true)
@TableName("station")
@ApiModel(value = "Station对象", description = "")
public class Station extends Model<Station> {

    @TableId(value = "StationID", type = IdType.AUTO)
    private Integer stationID;

    @TableField("StationName")
    private String stationName;

    @TableField("LineNumber")
    private Integer lineNumber;

    @TableField("IsExchange")
    private Integer isExchange;

    @Override
    public Serializable pkVal() {
        return this.stationID;
    }
}

package com.example.underground.entity;

import java.util.*;

public class Subway {
    
    public List<String> getStationsBetween(String startStation, String endStation, List<List<String>> allSubwayStations) {
        List<String> stationsBetween = new ArrayList<>();
        Map<String, List<String>> graph = buildGraph(allSubwayStations);
        
        // 检查起始站和终点站是否存在于地铁网络中
        if (!graph.containsKey(startStation) || !graph.containsKey(endStation)) {
            System.out.println("起始站或终点站不在地铁网络中");
            return stationsBetween;
        }
        
        // 使用BFS搜索起始站到终点站之间的所有站点
        Queue<String> queue = new LinkedList<>();
        Set<String> visited = new HashSet<>();
        Map<String, String> parentMap = new HashMap<>();
        
        queue.offer(startStation);
        visited.add(startStation);
        
        while (!queue.isEmpty()) {
            String currentStation = queue.poll();
            if (currentStation.equals(endStation)) {
                // 找到终点站，构建站点路径并返回
                String station = endStation;
                while (!station.equals(startStation)) {
                    stationsBetween.add(station);
                    station = parentMap.get(station);
                }
                stationsBetween.add(startStation);
                Collections.reverse(stationsBetween);
                return stationsBetween;
            }
            
            List<String> neighbors = graph.get(currentStation);
            if (neighbors != null) {
                for (String neighbor : neighbors) {
                    if (!visited.contains(neighbor)) {
                        queue.offer(neighbor);
                        visited.add(neighbor);
                        parentMap.put(neighbor, currentStation);
                    }
                }
            }
        }
        
        // 如果没有找到路径，返回空列表
        System.out.println("无法找到起始站到终点站之间的路径");
        return stationsBetween;
    }
    
    // 构建地铁站点图
    private Map<String, List<String>> buildGraph(List<List<String>> allSubwayStations) {
        Map<String, List<String>> graph = new HashMap<>();
        for (List<String> lineStations : allSubwayStations) {
            for (int i = 0; i < lineStations.size(); i++) {
                String station = lineStations.get(i);
                if (!graph.containsKey(station)) {
                    graph.put(station, new ArrayList<>());
                }
                if (i > 0) {
                    String prevStation = lineStations.get(i - 1);
                    graph.get(station).add(prevStation);
                    graph.get(prevStation).add(station);
                }
            }
        }
        return graph;
    }

}