AtCoderのABC    次のABCの問題へ    前のABCの問題へ

ABC363-E Sinking Land


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("3 3 5");
            WillReturn.Add("10 2 10");
            WillReturn.Add("3 1 4");
            WillReturn.Add("10 5 10");
            //9
            //7
            //6
            //5
            //4
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 5 3");
            WillReturn.Add("2 2 3 3 3");
            WillReturn.Add("2 1 2 1 3");
            WillReturn.Add("2 2 3 3 3");
            //15
            //7
            //0
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        long[] wkArr = InputList[0].Split(' ').Select(pX => long.Parse(pX)).ToArray();
        long TotalYear = wkArr[2];

        long[,] BanArr = CreateBanArr(InputList.Skip(1));
        long UB_X = BanArr.GetUpperBound(0);
        long UB_Y = BanArr.GetUpperBound(1);

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

        var VisitedPosSet = new HashSet<long>();

        // 外周をPQueueにInsert
        for (int Y = 0; Y <= UB_Y; Y++) {
            for (int X = 0; X <= UB_X; X++) {
                if (Y == 0 || Y == UB_Y || X == 0 || X == UB_X) {
                    WillEnqueue.Val = BanArr[X, Y];
                    WillEnqueue.X = X;
                    WillEnqueue.Y = Y;
                    InsPQueue.Enqueue(WillEnqueue);
                    VisitedPosSet.Add(GetHash(X, Y));
                }
            }
        }

        long CurrYear = 0;
        long SinkCnt = 0;
        while (InsPQueue.Count() > 0) {
            PQueue_Arr.PQueueJyoutaiDef Dequeued = InsPQueue.Dequeue();
            CurrYear = Math.Max(CurrYear, Dequeued.Val);
            long Hash = GetHash(Dequeued.X, Dequeued.Y);
            VisitedPosSet.Add(Hash);

            AnswerDef WillAdd;
            WillAdd.Year = CurrYear;
            WillAdd.SinkCnt = ++SinkCnt;
            mAnswerList.Add(WillAdd);

            Action<long, long> EnqueueAct = (pX, pY) =>
            {
                if (pX < 0 || UB_X < pX) return;
                if (pY < 0 || UB_Y < pY) return;

                long CurrHash = GetHash(pX, pY);
                if (VisitedPosSet.Add(CurrHash)) {
                    WillEnqueue.X = pX;
                    WillEnqueue.Y = pY;
                    WillEnqueue.Val = BanArr[pX, pY];
                    InsPQueue.Enqueue(WillEnqueue);
                }
            };

            EnqueueAct(Dequeued.X, Dequeued.Y - 1);
            EnqueueAct(Dequeued.X, Dequeued.Y + 1);
            EnqueueAct(Dequeued.X - 1, Dequeued.Y);
            EnqueueAct(Dequeued.X + 1, Dequeued.Y);
        }

        Dictionary<long, long> ResultDict = mAnswerList.GroupBy(pX => pX.Year).
            ToDictionary(pX => pX.Key, pX => pX.Max(Item => Item.SinkCnt));

        var sb = new System.Text.StringBuilder();
        long AllShimaCnt = (UB_X + 1) * (UB_Y + 1);
        long CurrShimaCnt = AllShimaCnt;
        for (long I = 1; I <= TotalYear; I++) {
            if (ResultDict.ContainsKey(I)) {
                CurrShimaCnt = AllShimaCnt - ResultDict[I];
            }
            sb.Append(CurrShimaCnt);
            sb.AppendLine();
        }
        Console.Write(sb.ToString());
    }

    struct AnswerDef
    {
        internal long Year;
        internal long SinkCnt;
    }
    static List<AnswerDef> mAnswerList = new List<AnswerDef>();

    ////////////////////////////////////////////////////////////////
    // IEnumerable<string>をlongの2次元配列に設定する
    ////////////////////////////////////////////////////////////////
    static long[,] CreateBanArr(IEnumerable<string> pStrEnum)
    {
        var StrList = pStrEnum.ToList();
        if (StrList.Count == 0) {
            return new long[0, 0];
        }

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

        SplitAct(StrList[0]);

        long UB_X = IntArr.GetUpperBound(0);
        long UB_Y = StrList.Count - 1;

        long[,] WillReturn = new long[UB_X + 1, UB_Y + 1];

        for (long Y = 0; Y <= UB_Y; Y++) {
            SplitAct(StrList[(int)Y]);
            for (long X = 0; X <= UB_X; X++) {
                WillReturn[X, Y] = IntArr[X];
            }
        }
        return WillReturn;
    }

    static long GetHash(long pX, long pY)
    {
        return pX * 10000 + pY;
    }
}

#region PQueue_Arr
// 内部で配列使用の優先度付きキュー (根のValが最小)
internal class PQueue_Arr
{
    internal struct PQueueJyoutaiDef
    {
        internal long Val;
        internal long X;
        internal long Y;
    }

    private PQueueJyoutaiDef[] mHeapArr;
    private long mHeapArrCnt = 0;

    // コンストラクタ
    internal PQueue_Arr()
    {
        mHeapArr = new PQueueJyoutaiDef[65535];
    }

    internal bool IsEmpty()
    {
        return mHeapArrCnt == 0;
    }

    internal long Count()
    {
        return mHeapArrCnt;
    }

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

    // エンキュー処理
    internal void Enqueue(PQueueJyoutaiDef pAddJyoutai)
    {
        long CurrNode = 1 + mHeapArrCnt;
        if (mHeapArr.GetUpperBound(0) < CurrNode) {
            ExtendArr();
        }

        mHeapArr[CurrNode] = pAddJyoutai;
        mHeapArrCnt++;

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

            CurrNode /= 2;
        }
    }

    // 配列のExtend
    private void ExtendArr()
    {
        PQueueJyoutaiDef[] NewHeapArr = new PQueueJyoutaiDef[mHeapArrCnt * 2];
        mHeapArr.CopyTo(NewHeapArr, 0);
        mHeapArr = NewHeapArr;
    }

    // デキュー処理
    internal PQueueJyoutaiDef Dequeue()
    {
        PQueueJyoutaiDef TopNode = mHeapArr[1];
        long LastNode = mHeapArrCnt;
        mHeapArr[1] = mHeapArr[LastNode];
        mHeapArrCnt--;

        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 (mHeapArrCnt <= 1) {
            return;
        }

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

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

        if (Left <= mHeapArrCnt && mHeapArr[Left].Val < Smallest) {
            Smallest = mHeapArr[Left].Val;
            SmallestNode = Left;
        }
        if (Right <= mHeapArrCnt && mHeapArr[Right].Val < Smallest) {
            Smallest = mHeapArr[Right].Val;
            SmallestNode = Right;
        }

        // 子ノードのほうが小さい場合
        if (SmallestNode != pRootNode) {
            PQueueJyoutaiDef Swap = mHeapArr[SmallestNode];
            mHeapArr[SmallestNode] = mHeapArr[pRootNode];
            mHeapArr[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
次に沈む島を管理してます。