ABC031-D 語呂合わせ

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("6 4");
            WillReturn.Add("356 migoro");
            WillReturn.Add("461 yoroi");
            WillReturn.Add("2 ni");
            WillReturn.Add("12 ini");
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 4");
            WillReturn.Add("21 aaa");
            WillReturn.Add("12 aaa");
            WillReturn.Add("123 aaaaaa");
            WillReturn.Add("13 aaaa");
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("2 3");
            WillReturn.Add("12211 abcaaaaabcabc");
            WillReturn.Add("2121 aaabcaaabc");
            WillReturn.Add("222221 aaaaaaaaaaabc");
        }
        else if (InputPattern == "Input4") {
            WillReturn.Add("2 1");
            WillReturn.Add("12 abcab");
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    struct VWInfoDef
    {
        internal string V;
        internal string W;
    }
    static List<VWInfoDef> mVWInfoList = new List<VWInfoDef>();

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

        int[] wkArr = InputList[0].Split(' ').Select(pX => int.Parse(pX)).ToArray();
        int K = wkArr[0];

        foreach (string EachStr in InputList.Skip(1)) {
            string[] SplitArr = EachStr.Split(' ');
            VWInfoDef WillAdd;
            WillAdd.V = SplitArr[0];
            WillAdd.W = SplitArr[1];
            mVWInfoList.Add(WillAdd);
        }

        IEnumerable<int[]> Query =
            RubyPatternClass<int>.RepeatedPermutation(new int[] { 1, 2, 3 }, K);

        foreach (int[] EachLenArr in Query) {
            bool HasAnswer;
            Dictionary<char, string> StrDict;
            DeriveAnswer(EachLenArr, out HasAnswer, out StrDict);
            if (HasAnswer) {
                foreach (var EachPair in StrDict.OrderBy(pX => pX.Key)) {
                    Console.WriteLine(EachPair.Value);
                }
                break;
            }
        }
    }

    // 1から9に対応する長さの配列を引数として、解の有無と解を返す
    static void DeriveAnswer(int[] pLenArr, out bool pHasAnswer, out Dictionary<char, string> pStrDict)
    {
        pHasAnswer = false;

        // 確定した文字列[数字]なDict
        pStrDict = new Dictionary<char, string>();

        foreach (VWInfoDef EachVWInfo in mVWInfoList) {
            string WArr = EachVWInfo.W;
            foreach (char EachNum in EachVWInfo.V) {
                int StrLen = pLenArr[EachNum - '1'];

                // 長さ不足ならNG
                if (WArr.Length < StrLen) return;

                // 既出だが、異なる文字ならNG
                if (pStrDict.ContainsKey(EachNum)) {
                    if (WArr.StartsWith(pStrDict[EachNum]) == false) {
                        return;
                    }
                }

                pStrDict[EachNum] = WArr.Substring(0, StrLen);
                WArr = WArr.Substring(StrLen);
            }
            // 文字が残ってたらNG
            if (WArr.Length > 0) {
                return;
            }
        }
        pHasAnswer = true;
    }
}

#region RubyPatternClass
// Rubyの場合の数
internal static class RubyPatternClass<Type>
{
    // 重複順列を返す
    private struct JyoutaiDef_RepeatedPermutation
    {
        internal List<int> SelectedIndList;
    }
    internal static IEnumerable<Type[]> RepeatedPermutation(IEnumerable<Type> pEnum, int pR)
    {
        if (pR == 0) yield break;
        Type[] pArr = pEnum.ToArray();

        var Stk = new Stack<JyoutaiDef_RepeatedPermutation>();
        JyoutaiDef_RepeatedPermutation WillPush;
        for (int I = pArr.GetUpperBound(0); 0 <= I; I--) {
            WillPush.SelectedIndList = new List<int>() { I };
            Stk.Push(WillPush);
        }

        while (Stk.Count > 0) {
            JyoutaiDef_RepeatedPermutation Popped = Stk.Pop();

            // クリア判定
            if (Popped.SelectedIndList.Count == pR) {
                var WillReturn = new List<Type>();
                Popped.SelectedIndList.ForEach(X => WillReturn.Add(pArr[X]));
                yield return WillReturn.ToArray();
                continue;
            }

            for (int I = pArr.GetUpperBound(0); 0 <= I; I--) {
                WillPush.SelectedIndList = new List<int>(Popped.SelectedIndList) { I };
                Stk.Push(WillPush);
            }
        }
    }
}
#endregion

解説

1から9の数字に割り当てる長さが、1以上3以下で
3の9乗 = 19683
なので、長さの組み合わせを全探索してます。