Submission #111859

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Source Code Expand

using System;
using System.Linq;
using System.Collections.Generic;
using System.Text.RegularExpressions;

class T
{
    public static void Main()
    {
        var NM = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        var dict = new Dictionary<int, Node>();
        for (int i = 1; i <= NM[0]; i++)
        {
            dict.Add(i, new Node(i));
        }

        for (var i = 0; i < NM[1]; i++)
        {
            var xy = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
            dict[xy[0]].AddWayTo(dict[xy[1]]);
            dict[xy[1]].AddWayTo(dict[xy[0]]);
        }

        int max = 1;

        for (int i = 1; i <= NM[0]; i++)
        {
            if (dict.ContainsKey(i))
            {
                var al = new Dictionary<int, bool>();
                for (int k = 1; k <= NM[0]; k++)
                {
                    al.Add(k, false);
                }
                int count = SearchNode(i, i, dict, al, 12, 0);
                if (count > max) max = count;
            }
        }
        Console.WriteLine("{0}", max+1);
    }

    public static int SearchNode(int now, int to, Dictionary<int, Node> dict, Dictionary<int, bool> avail, int rest, int count)
    {
        if(rest == 0) return count;

        avail.Remove(now);
        avail.Add(now, true);

        int nowc = count;

        foreach (var v in dict[now].NextNodeList)
        {
            if (v.Number == to) continue;

            if (!avail[v.Number])
            {
                int res = SearchNode(v.Number, to, dict, avail, rest - 1, count + 1);

                if (res > count) nowc = res;
            }
        }

        count = nowc;

        avail.Remove(now);
        avail.Add(now, false);

        return count;
    }

    private static string mul(string a, int n)
    {
        var r = "";
        for (int i = 0; i < n; i++)
        {
            r += a;
        }
        return a;
    }

    public class Node
    {
        public Node(int number)
        {
            Number = number;
            nexts = new List<Node>();
        }

        public void AddWayTo(Node next)
        {
            nexts.Add(next);
        }

        public int Number
        {
            private set;
            get;
        }

        public List<Node> NextNodeList
        {
            get { return nexts; }
        }

        private List<Node> nexts;
    }
}

Submission Info

Judge Result