ABC159-E Dividing Chocolate

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 5 4");
            WillReturn.Add("11100");
            WillReturn.Add("10001");
            WillReturn.Add("00111");
            //2
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 5 8");
            WillReturn.Add("11100");
            WillReturn.Add("10001");
            WillReturn.Add("00111");
            //0
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("4 10 4");
            WillReturn.Add("1110010010");
            WillReturn.Add("1000101110");
            WillReturn.Add("0011101001");
            WillReturn.Add("1101000111");
            //3
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static int UB_X;
    static int UB_Y;

    static void Main()
    {
        List<string> InputList = GetInputList();
        int[] wkArr = InputList[0].Split(' ').Select(pX => int.Parse(pX)).ToArray();
        int K = wkArr[2];

        int[,] BanArr = CreateBanArr(InputList.Skip(1));
        UB_X = BanArr.GetUpperBound(0);
        UB_Y = BanArr.GetUpperBound(1);

        List<JoutaiDef> DFSResultList = ExecDFS();

        int Answer = int.MaxValue;

        foreach (JoutaiDef EachDFSResult in DFSResultList) {
            List<int> ClearIndList = EachDFSResult.ClearIndList;
            int[] SumArr = new int[ClearIndList.Count + 1];

            int AnswerKouho = ClearIndList.Count;

            bool IsNG = false;
            for (int LoopX = 0; LoopX <= UB_X; LoopX++) {
                int YInd = 0;
                int[] CurrSumArr = new int[ClearIndList.Count + 1];
                for (int LoopY = 0; LoopY <= UB_Y; LoopY++) {
                    CurrSumArr[YInd] += BanArr[LoopX, LoopY];

                    if (ClearIndList.Contains(LoopY)) {
                        YInd++;
                    }
                }

                // 現在の列で、Kマスを超える場合は不可
                if (CurrSumArr.Max() > K) {
                    IsNG = true;
                    break;
                }

                // 現在の列の分を足すとKを超える場合は、分割が必要
                bool NeedDiv = false;
                for (int I = 0; I <= SumArr.GetUpperBound(0); I++) {
                    SumArr[I] += CurrSumArr[I];
                    if (SumArr[I] > K) {
                        NeedDiv = true;
                        break;
                    }
                }

                if (NeedDiv) {
                    AnswerKouho++;
                    SumArr = (int[])CurrSumArr.Clone();
                }
            }
            if (IsNG == false) {
                Answer = Math.Min(Answer, AnswerKouho);
            }
        }
        Console.WriteLine(Answer);
    }

    struct JoutaiDef
    {
        internal List<int> ClearIndList;
        internal int CurrInd;
    }

    // DFSで、集計をクリアする行の組み合わせを全探索する
    static List<JoutaiDef> ExecDFS()
    {
        List<JoutaiDef> WillRetuen = new List<JoutaiDef>();

        var Stk = new Stack<JoutaiDef>();
        JoutaiDef WillPush;
        WillPush.ClearIndList = new List<int>();
        WillPush.CurrInd = 0;
        Stk.Push(WillPush);

        while (Stk.Count > 0) {
            JoutaiDef Popped = Stk.Pop();
            WillRetuen.Add(Popped);

            if (Popped.CurrInd > UB_Y) {
                continue;
            }

            for (int I = Popped.CurrInd; I <= UB_Y - 1; I++) {
                WillPush.CurrInd = I + 1;
                WillPush.ClearIndList = new List<int>(Popped.ClearIndList);
                WillPush.ClearIndList.Add(I);
                Stk.Push(WillPush);
            }
        }
        return WillRetuen;
    }

    ////////////////////////////////////////////////////////////////
    // IEnumerable<string>をintの2次元配列に設定する
    ////////////////////////////////////////////////////////////////
    static int[,] CreateBanArr(IEnumerable<string> pStrEnum)
    {
        var StrList = pStrEnum.ToList();
        if (StrList.Count == 0) {
            return new int[0, 0];
        }

        int UB_X = StrList[0].Length - 1;
        int UB_Y = StrList.Count - 1;

        int[,] WillReturn = new int[UB_X + 1, UB_Y + 1];

        for (int Y = 0; Y <= UB_Y; Y++) {
            for (int X = 0; X <= UB_X; X++) {
                WillReturn[X, Y] = StrList[Y][X] - '0';
            }
        }
        return WillReturn;
    }
}

解説

縦幅が最大10なので、縦の分割の組み合わせを
DFSで全探索してから、
横の分割は貪欲法を使ってます。