ТЕМА 27: Алгоритъм за търсене

private void button1_Click(object sender, EventArgs e)
        {
            int x; int l, r, m;
            int [] a = {2,3,5,6, 8, 9 };
            r = a.Length-1; l = 0;
            m = (l + r) / 2;
            try
            {
              
          
                x = Convert.ToInt32(textBox1.Text);

                while ((a[m] != x)&&(l<r))
                {
                  
                    if (a[m] < x) l = m + 1;
                    else if (a[m] > x) r = m - 1;
                    m = (l + r) / 2;
                   
                
                }
                if (a[m] == x) MessageBox.Show(" a["+ m+"]=" + a[m]);
                else MessageBox.Show("no");
            }
            catch (Exception ex)
            { MessageBox.Show(ex.Message); }

           
        }
    }