Write a program in C# Sharp to count the frequency of each element of an array ?

using System;  
public class Exercise8  
{  
    public static void Main() 
{
	int[] arr1 = new int[100];
	int[] fr1 = new int[100];
    int n, i, j, ctr;
       Console.Write("\n\nCount the frequency of each element of an array:\n");
       Console.Write("----------------------------------------------------\n");	
       Console.Write("Input the number of elements to be stored in the array :");
	   n = Convert.ToInt32(Console.ReadLine()); 	     
       Console.Write("Input {0} elements in the array :\n",n);
       for(i=0;i<n;i++)
            {
	      Console.Write("element - {0} : ",i);
   	      arr1[i] = Convert.ToInt32(Console.ReadLine()); 		  
		  fr1[i] = -1;
	    }
    for(i=0; i<n; i++)
    {
        ctr = 1;
        for(j=i+1; j<n; j++)
        {
            if(arr1[i]==arr1[j])
            {
                ctr++;
                fr1[j] = 0;
            }
        }
        if(fr1[i]!=0)
        {
            fr1[i] = ctr;
        }
    }
    Console.Write("\nThe frequency of all elements of the array : \n");
    for(i=0; i<n; i++)
    {
        if(fr1[i]!=0)
        {
            Console.Write("{0} occurs {1} times\n", arr1[i], fr1[i]);
        }
    }
  }	
}