A44 Change and Reverse

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 4");
            WillReturn.Add("1 4 8");
            WillReturn.Add("3 2");
            WillReturn.Add("2");
            WillReturn.Add("3 2");
            //2
            //8
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    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 N = wkArr[0];
        int UB = N - 1;

        int[] AArr = new int[UB + 1];
        for (int I = 0; I <= UB; I++) {
            AArr[I] = I + 1;
        }
        bool IsReverse = false;

        Func<int, int> GetReverseInd = (pInd) =>
        {
            return UB - pInd;
        };

        foreach (string EachStr in InputList.Skip(1)) {
            SplitAct(EachStr);
            int T = wkArr[0];
            if (T == 1) {
                int X = wkArr[1] - 1;
                int Y = wkArr[2];

                if (IsReverse) {
                    X = GetReverseInd(X);
                }
                AArr[X] = Y;
            }
            if (T == 2) {
                IsReverse = (IsReverse == false);
            }
            if (T == 3) {
                int X = wkArr[1] - 1;
                if (IsReverse) {
                    X = GetReverseInd(X);
                }
                Console.WriteLine(AArr[X]);
            }
        }
    }
}

解説

配列を反転中かを、bool型に持たせてます。