DPL_1_C: Knapsack Problem

問題へのリンク

C#のソース

using System;
using System.Collections.Generic;
using System.Linq;

// Q078 ナップザック問題 https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=DPL_1_C&lang=jp
class Program
{
    static string InputPattern = "InputX";

    static List<string> GetInputList()
    {
        var WillReturn = new List<string>();

        if (InputPattern == "Input1") {
            WillReturn.Add("4 8");
            WillReturn.Add("4 2");
            WillReturn.Add("5 2");
            WillReturn.Add("2 1");
            WillReturn.Add("8 3");
            //21
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("2 20");
            WillReturn.Add("5 9");
            WillReturn.Add("4 10");
            //10
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("3 9");
            WillReturn.Add("2 1");
            WillReturn.Add("3 1");
            WillReturn.Add("5 2");
            //27
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    struct ItemInfoDef
    {
        internal int V;
        internal int W;
    }

    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 W = wkArr[1];
        int UB = W;

        var ItemList = new List<ItemInfoDef>();
        foreach (string EachStr in InputList.Skip(1)) {
            SplitAct(EachStr);
            ItemInfoDef WillAdd;
            WillAdd.V = wkArr[0];
            WillAdd.W = wkArr[1];
            ItemList.Add(WillAdd);
        }

        // 最大価値[重さ合計]なDP表
        int[] DPArr = new int[UB + 1];

        foreach (ItemInfoDef EachItemInfo in ItemList) {
            for (int I = 0; I <= UB; I++) {
                int NewInd = I + EachItemInfo.W;
                if (UB < NewInd) break;

                int NewVal = DPArr[I] + EachItemInfo.V;

                if (DPArr[NewInd] < NewVal) {
                    DPArr[NewInd] = NewVal;
                }
            }
        }

        Console.WriteLine(DPArr.Max());
    }
}

解説

配るDPで解いてます。