Submission #521260

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Source Code Expand

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

namespace D_InnerCircle {
	class Program {
		static List<string> relations = new List<string>();
		static int maxSize = 1;
		static List<int> ngIDList = new List<int>();
		static int N;
		static int M;

		static void Main( string[] args ) {
			string[] header = Console.ReadLine().Split( ' ' );
			N = int.Parse( header[0] );
			M = int.Parse( header[1] );

			for( int i = 0; i < M; i++ ) {
				relations.Add( Console.ReadLine() );
			}

			for( int i = N; i >= 1; i-- ) {
				if( M >= ( i * ( i - 1 ) ) / 2 ) {
					maxSize = i;
					break;
				}
			}

			int circleID = 0;
			for( int i = 0; i < N; i++ ) {
				circleID += 1 << i;
			}


			Queue<int> queue = new Queue<int>();
			queue.Enqueue( circleID );

			int circleSize = 1;
			while( queue.Count != 0 ) {
				int id = queue.Dequeue();

				if( isCircle( id ) ) {
					circleSize = getMemberList( id ).Count;
					break;
				}


				for( int i = 0; i < N; i++ ) {
					int baseNumber = 1 << i;

					if( ( id & baseNumber ) == baseNumber ) {
						queue.Enqueue( id - baseNumber );
					}
				}

			}

			Console.WriteLine( circleSize );
		}

		private static List<int> getMemberList( int id ) {
			List<int> list = new List<int>();
			for( int i = 0; i < N; i++ ) {
				int baseNumber = 1 << i;
				if( baseNumber > id ) {
					break;
				}

				if( (id & baseNumber) == baseNumber ) {
					list.Add( i + 1);
				}
			}

			return list;
		}

		private static bool isCircle( int id ) {
			if( ngIDList.Contains( id ) ) {
				return false;
			}

			List<int> members = getMemberList( id );
			if( members.Count == 1 ) {
				return true;
			}

			if( members.Count > maxSize ) {
				ngIDList.Add( id );
				return false;
			}

			for( int i = 1; i < members.Count; i++ ) {
				string relation = members[0].ToString() + " " + members[i].ToString();
				if( !relations.Contains( relation ) ) {
					ngIDList.Add( id );
					return false;
				}
			}

			members.RemoveAt(0);
			return isCircle( getCircleID(members) );
		}

		private static int getCircleID( List<int> members ) {
			int id = 0;

			foreach( int member in members ) {
				id += 1 << ( member - 1 );
			}

			return id;
		}

	}
}

Submission Info

Judge Result