4자리 중복피하는 난수구하기

using System;
using System.IO;
 
namespace Randomize
{
	class CCard
	{
		private const int MAX_NUM = 30;
		private int[] numbers = new int[MAX_NUM];
 
		public CCard(int seed)
		{			
			Init(seed);
		}
 
		public void Init(int seed)
		{			
			Random rnd = new Random(seed);
			for(int i=0; i<MAX_NUM; i++)
			{
				numbers[i] = rnd.Next(1000, 10000);
			}			
		}
 
		public bool CompareTo(CCard cd )
		{
			int sameNumCount = 0;
 
			for(int i=0; i<MAX_NUM; i++)
			{
				if(numbers[i] == cd[i])
				{					
					if(++sameNumCount ==2)
						return true;
				}													
			}			
			return false;
		}
 
		public void print()
		{
			for(int i=0; i<MAX_NUM; i++)
			{
				if(i%5 == 0 && i !=0)
					Console.WriteLine();
 
				Console.Write(numbers[i]+ " ");                
			}
            Console.WriteLine();
            Console.WriteLine();                
		}
 
		public int this[int index]
		{
			get
			{
				if(index < MAX_NUM)
					return numbers<ol>
</ol>
;
				else
					throw new ArgumentException();
			}
			set
			{
				if(index < MAX_NUM)
					this.numbers<ol>
</ol>
 = value;
				else
					throw new ArgumentException();				
			}
		}		
	}
 
	class CRandom
	{
		[STAThread]
		static void Main(string[] args)
		{
		    const int MAX_CARD = 20000;
            CCard[] cardList = new CCard[MAX_CARD];
 
            FileStream fs = new FileStream("C:\\test.txt", FileMode.Create);
            StreamWriter sw = new StreamWriter(fs);
 
            for (int i = 0; i < cardList.Length; i++)
            {
                cardList[i] = new CCard(i);
                for (int j = 0; j < 30; j++)
                {
                    if (j % 5 == 0)
                        sw.WriteLine();  
 
                    sw.Write(cardList[i][j] + " ");                    
                }
                sw.WriteLine();
                sw.WriteLine();
            }                   
            fs.Close();
 
            // check for duplicate
            for (int i = 0; i < cardList.Length-1; i++)
            {
                for (int j = i + 1; j < cardList.Length - 1; j++)
                {
                    if (cardList[i].CompareTo(cardList[j]))
                    {
                        Console.WriteLine("Duplicate");
                    }
                }
            }              
		}
	}
}