Educational DP Contest B Frog2

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 3");
            WillReturn.Add("10 30 40 50 20");
            //30
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 1");
            WillReturn.Add("10 20 10");
            //20
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("2 100");
            WillReturn.Add("10 10");
            //0
        }
        else if (InputPattern == "Input4") {
            WillReturn.Add("10 4");
            WillReturn.Add("40 10 20 70 80 10 20 70 80 60");
            //40
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

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

        int[] wkArr = InputList[0].Split(' ').Select(X => int.Parse(X)).ToArray();
        int K = wkArr[1];

        int[] HArr = InputList[1].Split(' ').Select(X => int.Parse(X)).ToArray();
        int UB = HArr.GetUpperBound(0);

        // 最小コスト[現在位置] なDP表
        var DPDict = new Dictionary<int, int>();
        DPDict[0] = 0;

        for (int I = 0; I <= UB; I++) {
            if (DPDict.ContainsKey(I) == false) continue;

            Action<int> wkAct = (pNewInd) =>
            {
                if (pNewInd > UB) return;
                int NewVal = DPDict[I] + Math.Abs(HArr[I] - HArr[pNewInd]);

                if (DPDict.ContainsKey(pNewInd)) {
                    if (DPDict[pNewInd] <= NewVal) {
                        return;
                    }
                }
                DPDict[pNewInd] = NewVal;
            };
            for (int J = 1; J <= K; J++) {
                wkAct(I + J);
            }
        }
        Console.WriteLine(DPDict[UB]);
    }
}

解説

DPで解いてます。