ABC160-D Line++

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 2 4");
            //5
            //4
            //1
            //0
        }
        else if (InputPattern == "Input2") {
            WillReturn.Add("3 1 3");
            //3
            //0
        }
        else if (InputPattern == "Input3") {
            WillReturn.Add("7 3 7");
            //7
            //8
            //4
            //2
            //0
            //0
        }
        else if (InputPattern == "Input4") {
            WillReturn.Add("10 4 8");
            //10
            //12
            //10
            //8
            //4
            //1
            //0
            //0
            //0
        }
        else {
            string wkStr;
            while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
        }
        return WillReturn;
    }

    struct JyoutaiDef
    {
        internal int Level;
        internal int CurrNode;
    }

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

        int[] wkArr = InputList[0].Split(' ').Select(pX => int.Parse(pX)).ToArray();
        int N = wkArr[0];
        int X = wkArr[1];
        int Y = wkArr[2];

        int UB = N;
        int[,] KyoriArr = new int[UB + 1, UB + 1];

        for (int I = 1; I <= N; I++) {
            var Que = new Queue<JyoutaiDef>();
            JyoutaiDef WillEnqueue;
            WillEnqueue.Level = 0;
            WillEnqueue.CurrNode = I;
            Que.Enqueue(WillEnqueue);

            var VisitedSet = new HashSet<int>();
            while (Que.Count > 0) {
                JyoutaiDef Dequeued = Que.Dequeue();

                if (VisitedSet.Add(Dequeued.CurrNode) == false) {
                    continue;
                }
                KyoriArr[I, Dequeued.CurrNode] = Dequeued.Level;

                Action<int> EnqueueAct = pNewNode =>
                {
                    if (pNewNode < 1 || N < pNewNode) return;
                    if (VisitedSet.Contains(pNewNode)) return;

                    WillEnqueue.Level = Dequeued.Level + 1;
                    WillEnqueue.CurrNode = pNewNode;
                    Que.Enqueue(WillEnqueue);
                };

                EnqueueAct(Dequeued.CurrNode + 1);
                EnqueueAct(Dequeued.CurrNode - 1);

                if (Dequeued.CurrNode == X) {
                    EnqueueAct(Y);
                }
                if (Dequeued.CurrNode == Y) {
                    EnqueueAct(X);
                }
            }
        }

        var CntDict = new Dictionary<int, int>();

        for (int I = 1; I <= UB; I++) {
            for (int J = 1; J <= UB; J++) {
                int Kyori = KyoriArr[I, J];
                if (CntDict.ContainsKey(Kyori) == false) {
                    CntDict[Kyori] = 0;
                }
                CntDict[Kyori]++;
            }
        }

        for (int I = 1; I <= N - 1; I++) {
            if (CntDict.ContainsKey(I)) {
                Console.WriteLine(CntDict[I] / 2);
            }
            else {
                Console.WriteLine(0);
            }
        }
    }
}

解説

ワーシャルフロイド法を使ったらTLEしました。

全ての辺の距離が1なので、幅優先探索で解きました。