ABC323-D Merge Slimes

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");
            WillReturn.Add("3 3");
            WillReturn.Add("5 1");
            WillReturn.Add("6 1");
            //3
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3");
            WillReturn.Add("1 1");
            WillReturn.Add("2 1");
            WillReturn.Add("3 1");
            //3
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("1");
            WillReturn.Add("1000000000 1000000000");
            //13
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

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

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

        // 個数[スライムのサイズ]なDict
        var CntDict = new Dictionary<long, long>();

        // 見る必要があるサイズ
        var InsPQueueArr = new PQueue_Arr();
        PQueue_Arr.PQueueJyoutaiDef WillEnqueue;

        foreach (string EachStr in InputList.Skip(1)) {
            SplitAct(EachStr);
            long Size = wkArr[0];
            long Cnt = wkArr[1];
            if (CntDict.ContainsKey(Size) == false) {
                CntDict[Size] = 0;
            }
            CntDict[Size] += Cnt;

            WillEnqueue.Val = Size;
            InsPQueueArr.Enqueue(WillEnqueue);
        }

        long Answer = 0;
        while (InsPQueueArr.Count() > 0) {
            PQueue_Arr.PQueueJyoutaiDef Dequeued = InsPQueueArr.Dequeue();
            long CurrCnt = CntDict[Dequeued.Val];
            if (CurrCnt % 2 == 1) {
                Answer++;
                CurrCnt--;
            }
            long NextSize = Dequeued.Val * 2;
            if (CntDict.ContainsKey(NextSize) == false) {
                CntDict[NextSize] = 0;
            }

            if (CurrCnt / 2 > 0) {
                CntDict[NextSize] += CurrCnt / 2;
                WillEnqueue.Val = NextSize;
                InsPQueueArr.Enqueue(WillEnqueue);
            }
            CntDict[Dequeued.Val] = 0;
        }
        Console.WriteLine(Answer);
    }
}

#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;
    }

    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

スライムのサイズの昇順に合成してます。