计算地铁换乘--计算出所有的线路

地铁测试线路图

源码

public class StationSched
    {
        /// <summary>
        /// 所有的站点信息
        /// </summary>
        List<StationInfo> stations = new List<StationInfo>();

        /// <summary>
        /// 线路信息
        /// </summary>
        List<ShipInfo> lines = new List<ShipInfo>();

        /// <summary>
        /// 构造函数，初始化站点和线路信息
        /// </summary>
        public StationSched()
        {
            stations.Add(new StationInfo() { Sid = 1, Lid = 1 });//0
            stations.Add(new StationInfo() { Sid = 2, Lid = 1 });//1
            stations.Add(new StationInfo() { Sid = 3, Lid = 1 });//2
            stations.Add(new StationInfo() { Sid = 4, Lid = 1 });//3
            stations.Add(new StationInfo() { Sid = 5, Lid = 1 });//4
            stations.Add(new StationInfo() { Sid = 6, Lid = 1 });//5
            stations.Add(new StationInfo() { Sid = 7, Lid = 1 });//6

            stations.Add(new StationInfo() { Sid = 19, Lid = 2 });//7
            stations.Add(new StationInfo() { Sid = 18, Lid = 2 });
            stations.Add(new StationInfo() { Sid = 17, Lid = 2 });
            stations.Add(new StationInfo() { Sid = 3, Lid = 2 });
            stations.Add(new StationInfo() { Sid = 13, Lid = 2 });
            stations.Add(new StationInfo() { Sid = 16, Lid = 2 });


            stations.Add(new StationInfo() { Sid = 15, Lid = 3 });//13
            stations.Add(new StationInfo() { Sid = 14, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 13, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 12, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 11, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 5, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 10, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 9, Lid = 3 });
            stations.Add(new StationInfo() { Sid = 8, Lid = 3 });

            for (int i = 0; i < 6; i++)
            {
                lines.Add(new ShipInfo() { Curr = stations[i], Next = stations[i + 1] });
            }
            for (int i = 6; i > 0; i--)
            {
                lines.Add(new ShipInfo() { Curr = stations[i], Next = stations[i - 1] });
            }

            for (int i = 7; i < 12; i++)
            {
                lines.Add(new ShipInfo() { Curr = stations[i], Next = stations[i + 1] });
            }
            for (int i = 12; i > 7; i--)
            {
                lines.Add(new ShipInfo() { Curr = stations[i], Next = stations[i - 1] });
            }

            for (int i = 13; i < 21; i++)
            {
                lines.Add(new ShipInfo() { Curr = stations[i], Next = stations[i + 1] });
            }
            for (int i = 21; i > 13; i--)
            {
                lines.Add(new ShipInfo() { Curr = stations[i], Next = stations[i - 1] });
            }

        }

        /// <summary>
        /// 获取sid站点可以到达的站点信息，去除已经计算过的preid站点
        /// </summary>
        /// <param name="preid"></param>
        /// <param name="sid"></param>
        /// <returns></returns>
        public List<StationInfo> GetNext(int preid, int sid)
        {
            List<StationInfo> list = new List<StationInfo>();
            foreach (var item in lines)
            {
                if (item.Curr.Sid == sid && item.Next.Sid != preid) list.Add(item.Next);
            }
            return list;
        }

        /// <summary>
        /// 获取线路信息
        /// </summary>
        /// <param name="s">起始站点编号</param>
        /// <param name="e">结束站点编号</param>
        /// <returns></returns>
        public List<string> GetResult(int s, int e)
        {
            List<List<int>> temp = GetLine(s, e);
            List<string> result = new List<string>();
            List<List<int>> line = new List<List<int>>();
            foreach (var item in temp)
            {
                if (item.Count > 0 && item[item.Count - 1] == e)
                    line.Add(item);
            }
            string src = "";
            int currLine = -1;
            foreach (var item in line)
            {
                currLine = GetLineNumber(item[0], item[1]);
                src += "从[" + currLine + "号线]的[" + item[0] + "]上车";
                for (int i = 1; i < item.Count; i++)
                {
                    if (i == item.Count - 1)
                    {
                        src += ",在[" + item[i] + "]站点下车。";
                        result.Add(src);
                        src = "";
                        break;
                    }
                    int tempLine = GetLineNumber(item[i], item[i + 1]);
                    if (tempLine != currLine)
                    {
                        currLine = tempLine;
                        src += ",在[" + item[i] + "]站点换乘[" + currLine + "号线]";
                    }
                }

            }

            return result;
        }

        /// <summary>
        /// 根据相邻的两个点取当前的线路
        /// </summary>
        /// <param name="s"></param>
        /// <param name="e"></param>
        /// <returns></returns>
        private int GetLineNumber(int l, int r)
        {
            foreach (var item in lines)
            {
                if ((item.Curr.Sid == l && item.Next.Sid == r) || (item.Curr.Sid == r && item.Next.Sid == l))
                    return item.Next.Lid;
            }
            return -1;
        }

        /// <summary>
        /// 获取线路的ID集合
        /// </summary>
        /// <param name="s">起始站点编号</param>
        /// <param name="e">结束站点编号</param>
        /// <returns></returns>
        private List<List<int>> GetLine(int s, int e)
        {
            List<List<int>> result = new List<List<int>>();
            List<int> curr = new List<int>();
            curr.Add(s);
            result.Add(curr);
            int currLine = 0;
            int preSid = s;
            int currSid = s;
            while (true)
            {
                if (currLine >= result.Count) return result;
                currSid = result[currLine][result[currLine].Count - 1];
                if (currSid == e)
                {
                    currLine += 1;
                    continue;
                }
                if (result[currLine].Count > 1)
                    preSid = result[currLine][result[currLine].Count - 2];
                if (currSid <= 0)
                {
                    currLine += 1;
                    continue;
                }
                List<StationInfo> temp = GetNext(preSid, currSid);

                if (temp.Count == 0)
                {//某条线路到头
                    currLine += 1;
                }
                else if (temp.Count == 1)
                {//不需要换乘继续前进
                    result[currLine].Add(temp[0].Sid);
                }
                else
                {//需要换乘了。
                    for (int i = 1; i < temp.Count; i++)
                    {
                        if (!result[currLine].Contains(temp[i].Sid))
                        {//防止死循环，过滤掉已经计算过的站点。
                            result.Add(result[currLine].GetRange(0, result[currLine].Count));
                            result[result.Count - 1].Add(temp[i].Sid);
                        }
                    }
                    result[currLine].Add(temp[0].Sid);
                }
            }
        }
    }



    /// <summary>
    /// 站点信息
    /// </summary>
    public class StationInfo
    {
        public int Lid { get; set; }
        public int Sid { get; set; }

        public override string ToString()
        {
            return "Sid:" + Sid + "--Lid:" + Lid;
        }
    }

    /// <summary>
    /// 关系信息
    /// </summary>
    public class ShipInfo
    {
        public StationInfo Curr { get; set; }
        public StationInfo Next { get; set; }

        public override string ToString()
        {
            return "Curr:" + Curr.Sid + "--Next:" + Next.Sid;
        }
    }

调用 

StationSched ss = new StationSched();
            List<string> lines = ss.GetResult(16, 4);
            for (int i = 0; i < lines.Count; i++)
            {
                Console.WriteLine(lines[i]);
            }
            Console.ReadLine();

 输出结果