ABC185-C Duodecim Ferra

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("12");
            //1
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("13");
            //12
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("17");
            //4368
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static void Main()
    {
        List<string> InputList = GetInputList();
        long L = long.Parse(InputList[0]);

        // 場合の数[分割数]なDP表
        long[] PrevDP = new long[12];
        PrevDP[0] = 1;

        for (int I = 2; I <= L; I++) {
            long[] CurrDP = (long[])PrevDP.Clone();
            for (int J = 0; J <= 10; J++) {
                if (PrevDP[J] == 0) continue;
                CurrDP[J + 1] += PrevDP[J];
            }
            PrevDP = CurrDP;
        }
        Console.WriteLine(PrevDP[11]);
    }
}

解説

動的計画法で解いてます。