ABC305-E Art Gallery on Graph

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 2");
            WillReturn.Add("2 3");
            WillReturn.Add("2 4");
            WillReturn.Add("3 5");
            WillReturn.Add("1 5");
            WillReturn.Add("1 1");
            WillReturn.Add("5 2");
            //4
            //1 2 3 5
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 0 1");
            WillReturn.Add("2 3");
            //1
            //2
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("10 10 2");
            WillReturn.Add("2 1");
            WillReturn.Add("5 1");
            WillReturn.Add("6 1");
            WillReturn.Add("2 4");
            WillReturn.Add("2 5");
            WillReturn.Add("2 10");
            WillReturn.Add("8 5");
            WillReturn.Add("8 6");
            WillReturn.Add("9 6");
            WillReturn.Add("7 9");
            WillReturn.Add("3 4");
            WillReturn.Add("8 2");
            //7
            //1 2 3 5 6 8 9
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }


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

    struct PersonDef
    {
        internal int Node;
        internal int HP;
    }
    static List<PersonDef> mPersonList = new List<PersonDef>();

    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]);
        int M = wkArr[1];

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

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

        foreach (string EachStr in InputList.Skip(1 + M)) {
            SplitAct(EachStr);
            PersonDef WillAdd;
            WillAdd.Node = wkArr[0];
            WillAdd.HP = wkArr[1];
            mPersonList.Add(WillAdd);
        }

        var InsPQueue = new PQueue();
        PQueue.PQueueJyoutaiDef WillEnqueue;

        var MemoDict = new Dictionary<long, long>();
        foreach (PersonDef EachPerson in mPersonList) {
            WillEnqueue.CurrNode = EachPerson.Node;
            WillEnqueue.Val = EachPerson.HP;
            InsPQueue.Enqueue(WillEnqueue);
            MemoDict[EachPerson.Node] = EachPerson.HP;
        }

        while (InsPQueue.IsEmpty() == false) {
            PQueue.PQueueJyoutaiDef Dequeued = InsPQueue.Dequeue();

            if (Dequeued.Val == 0) continue;

            int CurrNode = (int)Dequeued.CurrNode;

            if (mToNodeListDict.ContainsKey(CurrNode)) {
                foreach (int EachToNode in mToNodeListDict[CurrNode]) {
                    WillEnqueue.CurrNode = EachToNode;
                    WillEnqueue.Val = Dequeued.Val - 1;

                    if (MemoDict.ContainsKey(EachToNode)) {
                        if (MemoDict[EachToNode] >= WillEnqueue.Val) {
                            continue;
                        }
                    }
                    MemoDict[EachToNode] = WillEnqueue.Val;
                    InsPQueue.Enqueue(WillEnqueue);
                }
            }
        }

        Console.WriteLine(MemoDict.Count);

        var AnnswerList = new List<long>();
        foreach (long EachNode in MemoDict.Keys.OrderBy(pX => pX)) {
            AnnswerList.Add(EachNode);
        }
        Console.WriteLine(LongEnumJoin(" ", AnnswerList));
    }

    // セパレータとLong型の列挙を引数として、結合したstringを返す
    static string LongEnumJoin(string pSeparater, IEnumerable<long> pEnum)
    {
        string[] StrArr = Array.ConvertAll(pEnum.ToArray(), pX => pX.ToString());
        return string.Join(pSeparater, StrArr);
    }
}

#region PQueue
// 優先度付きキュー (根のValが最大)
internal class PQueue
{
    internal struct PQueueJyoutaiDef
    {
        internal long CurrNode;
        internal long Val;
    }

    private Dictionary<long, PQueueJyoutaiDef> mHeapDict = new Dictionary<long, PQueueJyoutaiDef>();

    internal bool IsEmpty()
    {
        return mHeapDict.Count == 0;
    }

    internal long Count()
    {
        return mHeapDict.Count;
    }

    internal long Peek()
    {
        return mHeapDict[1].Val;
    }

    // エンキュー処理
    internal void Enqueue(PQueueJyoutaiDef pAddJyoutai)
    {
        long CurrNode = 1 + mHeapDict.Count;
        mHeapDict[CurrNode] = pAddJyoutai;

        while (1 < CurrNode && mHeapDict[CurrNode / 2].Val < mHeapDict[CurrNode].Val) {
            PQueueJyoutaiDef Swap = mHeapDict[CurrNode];
            mHeapDict[CurrNode] = mHeapDict[CurrNode / 2];
            mHeapDict[CurrNode / 2] = Swap;

            CurrNode /= 2;
        }
    }

    // デキュー処理
    internal PQueueJyoutaiDef Dequeue()
    {
        PQueueJyoutaiDef TopNode = mHeapDict[1];
        long LastNode = mHeapDict.Count;
        mHeapDict[1] = mHeapDict[LastNode];
        mHeapDict.Remove(LastNode);

        MinHeapify(1);
        return TopNode;
    }

    // 根ノードを指定し、根から葉へヒープ構築
    private void MinHeapify(long pRootNode)
    {
        if (mHeapDict.Count <= 1) {
            return;
        }

        long Left = pRootNode * 2;
        long Right = pRootNode * 2 + 1;

        // 左の子、自分、右の子で値が最大のノードを選ぶ
        long Smallest = mHeapDict[pRootNode].Val;
        long SmallestNode = pRootNode;

        if (mHeapDict.ContainsKey(Left) && mHeapDict[Left].Val > Smallest) {
            Smallest = mHeapDict[Left].Val;
            SmallestNode = Left;
        }
        if (mHeapDict.ContainsKey(Right) && mHeapDict[Right].Val > Smallest) {
            Smallest = mHeapDict[Right].Val;
            SmallestNode = Right;
        }

        // 子ノードのほうが大きい場合
        if (SmallestNode != pRootNode) {
            PQueueJyoutaiDef Swap = mHeapDict[SmallestNode];
            mHeapDict[SmallestNode] = mHeapDict[pRootNode];
            mHeapDict[pRootNode] = Swap;

            // 再帰的に呼び出し
            MinHeapify(SmallestNode);
        }
    }
}
#endregion

解説

プライオリティキューで
体力の多い警備員から、各ノードを訪問してます。