ABC277-E Crystal Switches

問題へのリンク

C#のソース

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("5 5 2");
            WillReturn.Add("1 3 0");
            WillReturn.Add("2 3 1");
            WillReturn.Add("5 4 1");
            WillReturn.Add("2 1 1");
            WillReturn.Add("1 4 0");
            WillReturn.Add("3 4");
            //5
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("4 4 2");
            WillReturn.Add("4 3 0");
            WillReturn.Add("1 2 1");
            WillReturn.Add("1 2 0");
            WillReturn.Add("2 1 1");
            WillReturn.Add("2 4");
            //-1
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static int mGoalNode;
    static int mEdgeCnt;
    static int mSwitchCnt;

    // 隣接リスト
    static Dictionary<int, List<int>> mToNodeListDict0 = new Dictionary<int, List<int>>();
    static Dictionary<int, List<int>> mToNodeListDict1 = new Dictionary<int, List<int>>();

    static HashSet<int> mSSet = new HashSet<int>();

    static void Main()
    {
        List<string> InputList = GetInputList();

        int[] wkArr = { };
        Action<string> SplitAct = pStr =>
            wkArr = pStr.Split(' ').Select(pX => int.Parse(pX)).ToArray();

        SplitAct(InputList[0]);
        mGoalNode = wkArr[0];
        mEdgeCnt = wkArr[1];
        mSwitchCnt = wkArr[2];

        foreach (string EachStr in InputList.Skip(1).Take(mEdgeCnt)) {
            SplitAct(EachStr);
            int FromNode = wkArr[0];
            int ToNode = wkArr[1];

            Dictionary<int, List<int>> WorkPointer;
            if (wkArr[2] == 0) {
                WorkPointer = mToNodeListDict0;
            }
            else {
                WorkPointer = mToNodeListDict1;
            }

            if (WorkPointer.ContainsKey(FromNode) == false) {
                WorkPointer[FromNode] = new List<int>();
            }
            if (WorkPointer.ContainsKey(ToNode) == false) {
                WorkPointer[ToNode] = new List<int>();
            }
            WorkPointer[FromNode].Add(ToNode);
            WorkPointer[ToNode].Add(FromNode);
        }

        if (mSwitchCnt >= 1) {
            int[] SArr = InputList.Last().Split(' ').Select(pX => int.Parse(pX)).ToArray();
            mSSet.UnionWith(SArr);
        }

        Exec01BFS();
    }

    struct JyoutaiDef
    {
        internal int CurrNode;
        internal int Level;
        internal bool UseEdge1;
    }

    static void Exec01BFS()
    {
        var InsLinkedList = new LinkedList<JyoutaiDef>();
        JyoutaiDef WillEnqueue;
        WillEnqueue.CurrNode = 1;
        WillEnqueue.Level = 0;
        WillEnqueue.UseEdge1 = true;
        InsLinkedList.AddFirst(WillEnqueue);

        int Answer = int.MaxValue;
        bool FoundAnswer = false;

        var VisitedSet = new HashSet<int>();
        while (InsLinkedList.Count > 0) {
            JyoutaiDef Dequeued = InsLinkedList.First();
            InsLinkedList.RemoveFirst();

            if (Dequeued.CurrNode == mGoalNode) {
                FoundAnswer = true;
                Answer = Math.Min(Answer, Dequeued.Level);
                break;
            }

            Action<int, int, bool, bool> EnqueueAct = (pCurrNode, pLevel, pUseEdge1, pAddFirst) =>
            {
                WillEnqueue.CurrNode = pCurrNode;
                WillEnqueue.Level = pLevel;
                WillEnqueue.UseEdge1 = pUseEdge1;

                int Hash = GetHash(WillEnqueue);
                if (VisitedSet.Add(Hash) == false) {
                    return;
                }

                if (pAddFirst) {
                    InsLinkedList.AddFirst(WillEnqueue);
                }
                else {
                    InsLinkedList.AddLast(WillEnqueue);
                }
            };

            // スイッチを押す
            if (mSSet.Contains(Dequeued.CurrNode)) {
                EnqueueAct(Dequeued.CurrNode, Dequeued.Level, Dequeued.UseEdge1 == false, true);
            }

            // 移動する
            Dictionary<int, List<int>> WorkPointer;
            if (Dequeued.UseEdge1 == false) {
                WorkPointer = mToNodeListDict0;
            }
            else {
                WorkPointer = mToNodeListDict1;
            }

            if (WorkPointer.ContainsKey(Dequeued.CurrNode)) {
                foreach (int EachToNode in WorkPointer[Dequeued.CurrNode]) {
                    EnqueueAct(EachToNode, Dequeued.Level + 1, Dequeued.UseEdge1, false);
                }
            }
        }
        if (FoundAnswer) {
            Console.WriteLine(Answer);
        }
        else {
            Console.WriteLine(-1);
        }
    }

    static int GetHash(JyoutaiDef pJyoutai)
    {
        return pJyoutai.CurrNode * 10 + (pJyoutai.UseEdge1 ? 1 : 0);
    }
}

解説

01BFSで解いてます。