Lecture Notes on 22 Jul 2013

public class TestArray
{
  public static int[] reverseArray1 (int[] a)
  {
    int[] b = new int [a.length];
    for (int i = 0; i < a.length ; i++)
    {
      b[i] = a[a.length - 1 - i];   
    }
    return b;
  }

  public static int sumArray (int[] a)
  {
    int sum = 0;
    for (int i = 0; i < a.length; i++)
    {
      sum += a[i];
    }
    return sum;
  }

  public static int maxArray (int[] a)
  {
    int max = a[0];
    for (int i = 1; i < a.length; i++)
    {
      if (a[i] > max)
        max = a[i];
    }
    return max;
  }

  public static int max2Array (int[] a)
  {
     int max1, max2;
     if (a[0] > a[1])
     {
       max1 = a[0];
       max2 = a[1];
     }
     else
     {
       max1 = a[1];
       max2 = a[0];
     }

     for (int i = 2; i < a.length; i++)
     {
       if (a[i] > max1)
       {
         max2 = max1;
	 max1 = a[i];
       }
       else if (a[i] > max2)
       {
         max2 = a[i];
       }
     }
     return max2;
  }

  public static void reverseArray2 (int[] a)
  {
    int tmp = 0;
    for (int i = 0; i < a.length;  i++)
    {
      tmp = a[i];
      a[i] = a[a.length - 1 - i];
      a[a.length - 1 - i] = tmp;
    }
  }

  public static boolean isPalindromic (int[] a)
  {
    for (int i = 0; i < a.length / 2; i++)
    {
       if (a[i] != a[a.length - 1 - i])
         return false;
    }
    return true;
  }

  public static void main (String[] args)
  {
    int[] a = {8, 3, 6, 1, 5};

    for (int i = 0; i < a.length; i++)
    {
      System.out.println (a[i]);
    }
  }
}