ABC126-D Even Relation

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");
            WillReturn.Add("1 2 2");
            WillReturn.Add("2 3 1");
            //0
            //0
            //1
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("5");
            WillReturn.Add("2 5 2");
            WillReturn.Add("2 3 10");
            WillReturn.Add("1 3 8");
            WillReturn.Add("3 4 2");
            //1
            //0
            //1
            //0
            //1
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    struct NodeInfoDef
    {
        internal long ToNode;
        internal long Cost;
    }

    // 隣接リスト
    static Dictionary<long, List<NodeInfoDef>> mToNodeListDict =
        new Dictionary<long, List<NodeInfoDef>>();

    struct JyoutaiDef
    {
        internal long CurrNode;
        internal long CostSum;
    }

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

        long[] wkArr = { };
        Action<string> SplitAct = pStr =>
            wkArr = pStr.Split(' ').Select(pX => long.Parse(pX)).ToArray();

        long N = long.Parse(InputList[0]);

        foreach (string EachStr in InputList.Skip(1)) {
            SplitAct(EachStr);
            long FromNode = wkArr[0];
            long ToNode = wkArr[1];
            long Cost = wkArr[2];

            if (mToNodeListDict.ContainsKey(FromNode) == false) {
                mToNodeListDict[FromNode] = new List<NodeInfoDef>();
            }
            NodeInfoDef WillAdd1;
            WillAdd1.ToNode = ToNode;
            WillAdd1.Cost = Cost;
            mToNodeListDict[FromNode].Add(WillAdd1);

            if (mToNodeListDict.ContainsKey(ToNode) == false) {
                mToNodeListDict[ToNode] = new List<NodeInfoDef>();
            }
            NodeInfoDef WillAdd2;
            WillAdd2.ToNode = FromNode;
            WillAdd2.Cost = Cost;
            mToNodeListDict[ToNode].Add(WillAdd2);
        }

        // 色[頂点番号]なDict
        var AnswerDict = new Dictionary<long, long>();

        JyoutaiDef WillPush;
        WillPush.CurrNode = 1;
        WillPush.CostSum = 0;
        var Stk = new Stack<JyoutaiDef>();
        Stk.Push(WillPush);

        var VisitedSet = new HashSet<long>();
        while (Stk.Count > 0) {
            JyoutaiDef Popeed = Stk.Pop();

            AnswerDict[Popeed.CurrNode] = Popeed.CostSum % 2;

            foreach (NodeInfoDef EachToNode in mToNodeListDict[Popeed.CurrNode]) {
                if (VisitedSet.Add(EachToNode.ToNode) == false) {
                    continue;
                }

                WillPush.CurrNode = EachToNode.ToNode;
                WillPush.CostSum = Popeed.CostSum + EachToNode.Cost;
                Stk.Push(WillPush);
            }
        }
        foreach (var EachPair in AnswerDict.OrderBy(pX => pX.Key)) {
            Console.WriteLine(EachPair.Value);
        }
    }
}

解説

木なので、任意のノードから深さ優先探索を行い、
Cost合計が偶数なら0
Cost合計が奇数なら1
を割り振ってます。