B66 Typhoon

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 2");
            WillReturn.Add("1 2");
            WillReturn.Add("2 3");
            WillReturn.Add("4");
            WillReturn.Add("2 2 3");
            WillReturn.Add("1 2");
            WillReturn.Add("2 1 3");
            WillReturn.Add("1 1");
            //Yes
            //No
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("12 7");
            WillReturn.Add("8 11");
            WillReturn.Add("1 7");
            WillReturn.Add("10 12");
            WillReturn.Add("1 4");
            WillReturn.Add("4 8");
            WillReturn.Add("5 9");
            WillReturn.Add("3 5");
            WillReturn.Add("12");
            WillReturn.Add("2 6 8");
            WillReturn.Add("1 6");
            WillReturn.Add("2 10 12");
            WillReturn.Add("1 1");
            WillReturn.Add("1 5");
            WillReturn.Add("1 3");
            WillReturn.Add("2 3 5");
            WillReturn.Add("1 7");
            WillReturn.Add("2 3 6");
            WillReturn.Add("1 4");
            WillReturn.Add("1 2");
            WillReturn.Add("2 9 11");
            //No
            //Yes
            //Yes
            //No
            //No
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("4 3");
            WillReturn.Add("1 2");
            WillReturn.Add("2 3");
            WillReturn.Add("3 4");
            WillReturn.Add("7");
            WillReturn.Add("2 1 2");
            WillReturn.Add("2 1 3");
            WillReturn.Add("2 1 4");
            WillReturn.Add("1 2");
            WillReturn.Add("2 1 2");
            WillReturn.Add("2 1 3");
            WillReturn.Add("2 1 4");
            //Yes
            //Yes
            //Yes
            //Yes
            //No
            //No
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    static int mN;
    static int mM;

    struct EdgeDef
    {
        internal int FromNode;
        internal int ToNode;
    }
    static List<EdgeDef> mEdgeList = new List<EdgeDef>();

    class QueryDef
    {
        internal int Type;
        internal int CutEdgeInd;
        internal int FromNode;
        internal int ToNode;
        internal string Answer;
    }
    static List<QueryDef> mQueryList = new List<QueryDef>();

    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]);
        mN = wkArr[0];
        mM = wkArr[1];

        foreach (string EachStr in InputList.Skip(1).Take(mM)) {
            SplitAct(EachStr);
            EdgeDef WillAdd;
            WillAdd.FromNode = wkArr[0];
            WillAdd.ToNode = wkArr[1];
            mEdgeList.Add(WillAdd);
        }

        foreach (string EachStr in InputList.Skip(1 + mM + 1)) {
            SplitAct(EachStr);
            var WillAdd = new QueryDef();
            WillAdd.Type = wkArr[0];
            if (WillAdd.Type == 1) {
                WillAdd.CutEdgeInd = wkArr[1] - 1;
            }
            if (WillAdd.Type == 2) {
                WillAdd.FromNode = wkArr[1];
                WillAdd.ToNode = wkArr[2];
            }
            mQueryList.Add(WillAdd);
        }

        var CutEdgeSet = new HashSet<int>();
        foreach (QueryDef EachQuery in mQueryList) {
            if (EachQuery.Type == 1) {
                CutEdgeSet.Add(EachQuery.CutEdgeInd);
            }
        }

        var InsUnionFind = new UnionFind();
        for (int I = 1; I <= mN; I++) {
            InsUnionFind.MakeSet(I);
        }

        for (int I = 0; I <= mEdgeList.Count - 1; I++) {
            if (CutEdgeSet.Contains(I) == false) {
                InsUnionFind.Unite(mEdgeList[I].FromNode, mEdgeList[I].ToNode);
            }
        }

        for (int I = mQueryList.Count - 1; 0 <= I; I--) {
            if (mQueryList[I].Type == 1) {
                int Ind = mQueryList[I].CutEdgeInd;
                InsUnionFind.Unite(mEdgeList[Ind].FromNode, mEdgeList[Ind].ToNode);
            }
            if (mQueryList[I].Type == 2) {
                int FromNode = mQueryList[I].FromNode;
                int ToNode = mQueryList[I].ToNode;

                int Root1 = InsUnionFind.FindSet(FromNode);
                int Root2 = InsUnionFind.FindSet(ToNode);

                if (Root1 == Root2) {
                    mQueryList[I].Answer = "Yes";
                }
                else {
                    mQueryList[I].Answer = "No";
                }
            }
        }

        for (int I = 0; I <= mQueryList.Count - 1; I++) {
            if (mQueryList[I].Type == 2) {
                Console.WriteLine(mQueryList[I].Answer);
            }
        }
    }
}

#region UnionFind
// UnionFindクラス
internal class UnionFind
{
    private class NodeInfoDef
    {
        internal int ParentNode;
        internal int Rank;
    }
    private Dictionary<int, NodeInfoDef> mNodeInfoDict =
        new Dictionary<int, NodeInfoDef>();

    // 要素が1つである木を森に追加
    internal void MakeSet(int pNode)
    {
        NodeInfoDef WillAdd = new NodeInfoDef();
        WillAdd.ParentNode = pNode;
        WillAdd.Rank = 0;
        mNodeInfoDict[pNode] = WillAdd;
    }

    // 合併処理
    internal void Unite(int pX, int pY)
    {
        int XNode = FindSet(pX);
        int YNode = FindSet(pY);
        int XRank = mNodeInfoDict[XNode].Rank;
        int YRank = mNodeInfoDict[YNode].Rank;

        if (XRank > YRank) {
            mNodeInfoDict[YNode].ParentNode = XNode;
        }
        else {
            mNodeInfoDict[XNode].ParentNode = YNode;
            if (XRank == YRank) {
                mNodeInfoDict[YNode].Rank++;
            }
        }
    }

    // ノードを引数として、木の根を取得
    internal int FindSet(int pTargetNode)
    {
        // 根までの経路上のノードのList
        var PathNodeList = new List<int>();

        int CurrNode = pTargetNode;
        while (CurrNode != mNodeInfoDict[CurrNode].ParentNode) {
            PathNodeList.Add(CurrNode);
            CurrNode = mNodeInfoDict[CurrNode].ParentNode;
        }

        // 経路圧縮 (親ポインタの付け替え)
        foreach (int EachPathNode in PathNodeList) {
            mNodeInfoDict[EachPathNode].ParentNode = CurrNode;
        }
        return CurrNode;
    }

    internal void DebugPrint()
    {
        foreach (var EachPair in mNodeInfoDict.OrderBy(pX => pX.Key)) {
            Console.WriteLine("mNodeInfoDict[{0}].ParentNode={1}",
                EachPair.Key, EachPair.Value.ParentNode);
        }
    }
}
#endregion

解説

UnionFindの、切断処理は、計算量が悪いので、
クエリを先読みして、逆から解を求めてます。