Question

Possible Duplicate:
Any chance to get unique records using Linq (C#)?

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

namespace WaysOf100
{
class WaysOf100Test
{
    static void Main(string[] args)
    {
        WaysOf100 test= new WaysOf100();
        test.Go();
        test.EliminateDuplicates();
    }
}

class WaysOf100
{        
    List<string> results = new List<string>();             

    public void Go()
    {
        int num = 5, temp=0;//to store the intermediate difference
        for (int i = 1; i <num; i++)
        {
            temp = num - i;
            for (int j = 1; j <= temp; j++)
            {
                if (temp % j == 0)
                {   
                    //Console.Write(i + " ");
                    string text = "";                        
                    text = i.ToString();                        
                    for (int k = 1; k <= (temp / j); k++)
                    {
                        //Console.Write(j + " ");  
                        text += j.ToString();
                    }
                    char[] rev = text.ToCharArray();
                    Array.Reverse(rev);                       
                    if(!(results.Contains(rev.ToString())))
                        results.Add(text);                        

                }
            }                
        }
    }

    public void EliminateDuplicates()
    {            
        //To eliminate the duplicates   

        /*for (int i = 0; i < results.Count; i++)
        {

            for (int j = 0; j < results.Count; j++)
            {

                if (!(results[i].Equals(results[j])))
                {
                    char [] rev = results[j].ToCharArray();
                    Array.Reverse(rev);                        
                    if (results[i]==rev.ToString())
                        results.Remove(rev.ToString());
                }                                       
            }
        }*/

        foreach (var result in results)
        {
           Console.WriteLine(result);
        }
        Console.WriteLine("Total number of elements is :{0}",results.Count);
    }
}

}

The result so far is
11111
122
14
2111
23
311
32
41

This is what I want in short : the reverse of 41 is 14 and 14 already exists in the list so i don’t want to add 41. Similarly, the reverse of 32 is 23 which also exists and hence 32 should not be added. But this piece of could which I’ve written to achieve the functionality is not giving the desired results

if(!(results.Contains(rev.ToString())))
      results.Add(text);

Answer 1

The problem you are having is that rev.ToString()' returns "System.Char[]" and not the string value you wanted/expected. For your logic, try the following:

    public void EliminateDuplicates()
    {
        //Eliminate the duplicates    

        for (int i = 0; i < results.Count; i++)
        {
            for (int j = 0; j < results.Count; j++)
            {
                if (!(results[i].Equals(results[j])))
                {
                    char[] rev = results[j].ToCharArray();
                    char[] forward = results[i].ToCharArray();
                    Array.Reverse(rev);
                    bool bEqual = true;
                    for( int n = 0 ; n < results[j].Length && true == bEqual ; n++ )
                    {
                        if( rev[n] != forward[n] )
                        {
                            bEqual = false;
                        }
                    }
                    if( true == bEqual)
                        results.Remove(results[j] );
                }
            }
        }

        foreach (var result in results)
        {
            Console.WriteLine(result);
        }
        Console.WriteLine("Total number of elements is : {0} ", results.Count);
    }