C# array exercise: stem leaf

Exercise : Write a C# program to display an integer data set in the form of stem and leaf. The data points are input by the user from keyboard. This program will display the output similar to the one shown below:
  
If you are not sure how to display a data set in the form of stem and leaf, you will need to read this page:
Stem and Leaf display  
Solution:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Csharp_exercises
{
class Program
{
static void Main(string[] args)
{
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Projecttest
{
class Program
{
static void Main(string[] args)
{

  int n;
  Console.Write("Enter number of data points:");
  n = int.Parse(Console.ReadLine());
  if (n < 3)
   {
   Console.WriteLine("The number of data points should be greater than 2.");

    }
  else
  {

//declare an array of n size to store integral data points
  int[] dataset = new int[n];
//allow user inputs
   int i = 0;
   for (i = 0; i < n; i++)
  {
    Console.Write("[{0}]:", i);
    dataset[i] = int.Parse(Console.ReadLine());
   }

//sort the data set
   bubblesort(dataset, n);
//show data in stem and leaf display
//Display sorted array
  Console.WriteLine("The sorted array is:");
   for (i = 0; i < n; i++)
    {
      Console.Write("{0}\t", dataset[i]);
      if (i % 5 == 0 && i != 0) Console.Write("\n");
     }

//store stem and leaf in a 2D array
    int[,] stem_leaf = new int[n, 2];
    for (i = 0; i < n; i++)
    {
      stem_leaf[i, 0] = dataset[i] / 10;
      stem_leaf[i, 1] = dataset[i] % 10;
    }

//initialize 2D array storing numbers of occurences, and values
   int[,] mode = new int[n, 2];

   for (i = 0; i < n; i++)
     for (int j = 0; j < 2; j++) mode[i, j] = 0;

       mode[0, 0] = 1;
//find mode

   int count = 1;
   for (i = count - 1; i < n; i++)
   {
     for (int j = count - 1; j < n - 1; j++)
      {
        if (stem_leaf[i, 0] == stem_leaf[j + 1, 0]) { count++; mode[i, 0]++; mode[i, 1] = stem_leaf[i, 0]; }
       else if (i == 0) mode[i, 1] = stem_leaf[i, 0];
       }
   }
    Console.WriteLine();
    Console.WriteLine("Stem and Leaf Display:");
    Console.WriteLine("Frequency\tStem\tLeaf");
    Console.WriteLine("================================");
    int c = 0, leaf = 0;
    for (i = 0; i < n; i++)
     {
       if (mode[i, 1] != 0)
        {
          leaf += mode[i, 0];

          Console.Write("{0,-18}", mode[i, 0]);
          Console.Write("{0,-6}", mode[i, 1]);
          for (int j = c; j < leaf; j++)
            {
              Console.Write("{0}", stem_leaf[j, 1]);
             }

         c = leaf;
        Console.WriteLine();
      }
   }
 }
Console.ReadLine();
}

static void bubblesort(int[] dataset, int n)
{
  int i, j;
  for (i = 0; i < n; i++)
  for (j = n - 1; j > i; j--)
  if (dataset[j] < dataset[j - 1])
   {
     int temp = dataset[j];
     dataset[j] = dataset[j - 1];
     dataset[j - 1] = temp;
            }

      }

  }
}


}

}

}