第3回PAST L スーパーマーケット

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("2");
            WillReturn.Add("3 1 200 1000");
            WillReturn.Add("5 20 30 40 50 2");
            WillReturn.Add("5");
            WillReturn.Add("1 1 1 2 2");
            //20
            //30
            //40
            //200
            //1000
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("10");
            WillReturn.Add("6 8 24 47 29 73 13");
            WillReturn.Add("1 4");
            WillReturn.Add("5 72 15 68 49 16");
            WillReturn.Add("5 65 20 93 64 91");
            WillReturn.Add("6 100 88 63 50 90 44");
            WillReturn.Add("2 6 1");
            WillReturn.Add("10 14 2 76 28 21 78 43 11 97 70");
            WillReturn.Add("5 31 9 62 84 40");
            WillReturn.Add("8 10 46 96 23 98 19 38 51");
            WillReturn.Add("2 37 77");
            WillReturn.Add("20");
            WillReturn.Add("1 1 1 1 2 2 2 1 1 2 2 2 2 2 1 2 1 2 2 1");
            //100
            //88
            //72
            //65
            //93
            //77
            //68
            //63
            //50
            //90
            //64
            //91
            //49
            //46
            //44
            //96
            //37
            //31
            //62
            //20
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        long N = long.Parse(InputList[0]);

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

        var InsSegmentTree = new SegmentTree(N * 2, long.MinValue);

        // 棚ごとの消費期限のキュー
        var QueList = new List<Queue<long>>();

        // 棚[消費期限]なDict
        var TanaDict = new Dictionary<long, long>();

        long TanaID = 0;
        foreach (string EachStr in InputList.Skip(1).Take((int)N)) {
            SplitAct(EachStr);
            long[] CurrKArr = wkArr.Skip(1).ToArray();
            long UB = CurrKArr.GetUpperBound(0);

            foreach (long EachK in CurrKArr) {
                TanaDict[EachK] = TanaID;
            }

            var CurrQue = new Queue<long>(CurrKArr);
            QueList.Add(CurrQue);

            TanaID++;
        }

        for (long I = 0; I <= QueList.Count - 1; I++) {
            if (QueList[(int)I].Count > 0) {
                long K1 = QueList[(int)I].Dequeue();
                InsSegmentTree.Update(I, K1);
            }
            if (QueList[(int)I].Count > 0) {
                long K2 = QueList[(int)I].Dequeue();
                InsSegmentTree.Update(I + N, K2);
            }
        }

        var sb = new System.Text.StringBuilder();
        int[] AArr = InputList.Last().Split(' ').Select(pX => int.Parse(pX)).ToArray();
        foreach (long EachA in AArr) {
            long MaxKouho1 = InsSegmentTree.Internal_Query(0, N - 1);
            long MaxKouho2 = InsSegmentTree.Internal_Query(0, N * 2 - 1);
            long MaxVal;
            if (EachA == 1) {
                MaxVal = MaxKouho1;
            }
            else {
                MaxVal = Math.Max(MaxKouho1, MaxKouho2);
            }
            sb.AppendLine(MaxVal.ToString());
            long ExtractTanaID = TanaDict[MaxVal];

            long ExtractKouho1 = InsSegmentTree.Internal_Query(ExtractTanaID, ExtractTanaID);
            long ExtractKouho2 = InsSegmentTree.Internal_Query(ExtractTanaID + N, ExtractTanaID + N);

            Queue<long> CurrQue = QueList[(int)TanaDict[MaxVal]];

            if (MaxVal == ExtractKouho1) {
                InsSegmentTree.Update(ExtractTanaID, ExtractKouho2);
            }
            long Dequeued = long.MinValue;
            if (CurrQue.Count > 0) {
                Dequeued = CurrQue.Dequeue();
            }
            InsSegmentTree.Update(ExtractTanaID + N, Dequeued);
        }
        Console.Write(sb.ToString());
    }
}

#region SegmentTree
// SegmentTreeクラス (RMaxQ and 1点更新)
internal class SegmentTree
{
    private long[] mTreeNodeArr;
    private long UB; // 木のノードの配列のUB
    private long mLeafCnt; // 葉ノードの数
    private long mExternalArrUB;

    // ノードの添字を引数とし、範囲の開始添字と終了添字を持つ配列
    private struct RangeInfoDef
    {
        internal long StaInd;
        internal long EndInd;
    }
    private RangeInfoDef[] mRangeInfo;

    // ノードのIndexの列挙を返す
    internal IEnumerable<long> GetNodeIndEnum()
    {
        for (long I = 0; I <= mExternalArrUB; I++) {
            yield return I;
        }
    }

    // 木のノードのUBを返す
    internal long GetUB()
    {
        return mExternalArrUB;
    }

    // コンストラクタ
    internal SegmentTree(long pExternalArrUB, long pInitVal)
    {
        mExternalArrUB = pExternalArrUB;

        // 簡単のため、葉ノード数を2のべき乗に
        long ArrLength = 0;
        for (long I = 1; I < long.MaxValue; I *= 2) {
            ArrLength += I;
            mLeafCnt = I;

            if (pExternalArrUB + 1 < mLeafCnt) break;
        }

        // すべての値をpInitValに
        UB = ArrLength - 1;
        mTreeNodeArr = new long[UB + 1];
        for (long I = 0; I <= UB; I++) {
            mTreeNodeArr[I] = pInitVal;
        }

        // ノードの添字を引数とし、範囲の開始添字と終了添字を持つ配列の作成
        mRangeInfo = new RangeInfoDef[UB + 1];
        for (long I = 0; I <= UB; I++) {
            if (I == 0) {
                RangeInfoDef WillSet1;
                WillSet1.StaInd = 0;
                WillSet1.EndInd = mLeafCnt - 1;
                mRangeInfo[I] = WillSet1;
                continue;
            }
            long ParentNode = DeriveParentNode(I);
            RangeInfoDef ParentRangeInfo = mRangeInfo[ParentNode];

            RangeInfoDef WillSet2;
            long Mid = (ParentRangeInfo.StaInd + ParentRangeInfo.EndInd) / 2;

            if (I % 2 == 1) { // 奇数ノードの場合
                WillSet2.StaInd = ParentRangeInfo.StaInd;
                WillSet2.EndInd = Mid;
            }
            else { // 偶数ノードの場合
                WillSet2.StaInd = Mid + 1;
                WillSet2.EndInd = ParentRangeInfo.EndInd;
            }
            mRangeInfo[I] = WillSet2;
        }
    }

    // 親ノードの添字を取得
    private long DeriveParentNode(long pTarget)
    {
        return (pTarget - 1) / 2;
    }

    // 子ノードの添字(小さいほう)を取得
    private long DeriveChildNode(long pTarget)
    {
        return pTarget * 2 + 1;
    }

    // 葉ノードの配列の添字を木の添字に変換して返す
    private long DeriveTreeNode(long pLeafArrInd)
    {
        long BaseInd = UB - mLeafCnt + 1;
        return BaseInd + pLeafArrInd;
    }

    // 葉ノードの配列のK番目の値をNewValに変更
    internal void Update(long pK, long pNewVal)
    {
        long CurrNode = DeriveTreeNode(pK);
        mTreeNodeArr[CurrNode] = pNewVal;

        // 登りながら更新
        while (CurrNode > 0) {
            CurrNode = DeriveParentNode(CurrNode);
            long ChildNode1 = DeriveChildNode(CurrNode);
            long ChildNode2 = ChildNode1 + 1;
            mTreeNodeArr[CurrNode] =
                Math.Max(mTreeNodeArr[ChildNode1], mTreeNodeArr[ChildNode2]);
        }
    }

    // 開始添字と終了添字とカレントノードを引数として、最大値を返す
    internal long Internal_Query(long pSearchStaInd, long pSearchEndInd)
    {
        return Private_Query(pSearchStaInd, pSearchEndInd, 0);
    }
    private long Private_Query(long pSearchStaInd, long pSearchEndInd, long pCurrNode)
    {
        long CurrNodeStaInd = mRangeInfo[pCurrNode].StaInd;
        long CurrNodeEndInd = mRangeInfo[pCurrNode].EndInd;

        // OverLapしてなければ、long.MinValue
        if (CurrNodeEndInd < pSearchStaInd || pSearchEndInd < CurrNodeStaInd)
            return long.MinValue;

        // 完全に含んでいれば、このノードの値
        if (pSearchStaInd <= CurrNodeStaInd && CurrNodeEndInd <= pSearchEndInd)
            return mTreeNodeArr[pCurrNode];

        // そうでなければ、2つの子の最大値
        long ChildNode1 = DeriveChildNode(pCurrNode);
        long ChildNode2 = ChildNode1 + 1;

        long ChildVal1 = Private_Query(pSearchStaInd, pSearchEndInd, ChildNode1);
        long ChildVal2 = Private_Query(pSearchStaInd, pSearchEndInd, ChildNode2);
        return Math.Max(ChildVal1, ChildVal2);
    }
}
#endregion

解説

棚の先頭のみか
棚の先頭とその次
を見るので、
セグメント木でqueryの区間を2倍にすることで対応してます。