ABC407-E Most Valuable Parentheses

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");
            WillReturn.Add("400");
            WillReturn.Add("500");
            WillReturn.Add("200");
            WillReturn.Add("100");
            WillReturn.Add("300");
            WillReturn.Add("600");
            WillReturn.Add("6");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            WillReturn.Add("1000000000");
            //1200
            //6000000000
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        long[] NumArr = InputList.Skip(1).Select(pX => long.Parse(pX)).ToArray();
        long UB = NumArr.GetUpperBound(0);

        long CurrInd = 0;
        var sb = new System.Text.StringBuilder();
        while (true) {
            long Len = NumArr[CurrInd] * 2;
            var ValList = new List<long>();
            for (long I = CurrInd + 1; I <= CurrInd + 1 + Len - 1; I++) {
                ValList.Add(NumArr[I]);
            }
            long Result = Solve(ValList.ToArray());
            sb.Append(Result);
            sb.AppendLine();

            CurrInd += Len + 1;
            if (CurrInd > UB) break;
        }
        Console.Write(sb.ToString());
    }

    static long Solve(long[] pArr)
    {
        var InsPQueue = new PQueue();
        PQueue.PQueueJyoutaiDef WillEnqueue;

        long Answer = 0;
        for (long I = 0; I <= pArr.GetUpperBound(0); I++) {
            WillEnqueue.Val = pArr[I];
            InsPQueue.Enqueue(WillEnqueue);

            if (I % 2 == 0) {
                Answer += InsPQueue.Dequeue().Val;
            }
        }
        return Answer;
    }
}

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

3 1 4 1 5 9 2 6 5 3 5 9 8 7 6 5 4 3
で考えると
Ind0までに開き括弧1個
Ind2までに開き括弧2個
Ind4までに開き括弧3個
Ind6までに開き括弧4個
Ind8までに開き括弧5個
Ind10までに開き括弧6個
・・・
となるので、
プライオリティキューを使用してます。