OddMagicSquare.java

public class OddMagicSquare 
{
  public OddMagicSquare(int n)
  {
    if (isOdd(n))
    {    
      int [][] square = new int [n][n];
      
      int fillInteger = 1; 
      int colPointer = 0;
      int rowPointer = (n - 1)/2;
      
      while (fillInteger <= n*n)
      {
        square[colPointer][rowPointer] = fillInteger;
        colPointer = wrapAround(colPointer--,n);
        wrapAround(rowPointer++,n);
        fillInteger++;
      }}
    else
      throw new IllegalArgumentException("This system works for Odd Magic Squares only.");
    
    
  }
  public static boolean isMagic(int[][] a) 
  {
    
    if (checkRows(a) && checkCols(a) && checkDiags(a));
    return true;
  }
  
  public void main(String[] args)
  {
    System.out.println( "Welcome, and thanks for playing Odd Magic Square.  I'm your host your computer and we'll be playing this week with...your computer.\n\n" );
    System.out.println( "Let's go over the rules shall we? \n");
    System.out.println( "Rule 1, I can only handle positive integer inputs. \n");
    System.out.println( "Rule 2, I can only handle odd numbered integers. \n");
    System.out.println( "Rule 3, No chewing gum. \n");
  
  }
  
  private static boolean checkRows(int[][] a) {
    int rowCounter = 0;
    while (rowCounter < a.length)
    {
      int subTotal = 0;
      int colCounter = 0;
      while (colCounter < a.length)
      {
        subTotal = subTotal + a[colCounter][rowCounter];
        colCounter++;
        
      }
      if (subTotal != (a.length * (a.length*a.length + 1) / 2))
      {
        return false;
      }
      rowCounter++;   
    }
    return true;
  }
  
  
  private static boolean checkCols(int [][] a){
    int colCounter = 0;
    while (colCounter < a.length)
    {
      int subTotal = 0;
      int rowCounter = 0;
      while (rowCounter < a.length)
      {
        subTotal = subTotal + a[colCounter][rowCounter];
        rowCounter++;
        
      }
      if (subTotal != (a.length * (a.length*a.length + 1) / 2))
      {
        return false;
      }
      colCounter++;   
    }
    return true;
  }
  
  private static boolean checkDiags(int [][] a){
    int subTotal = 0;
    int colCounter = 0;
    int rowCounter = 0;
    while (colCounter < a.length)
    {
      subTotal = subTotal + a[colCounter][rowCounter];
      colCounter++;
      rowCounter++;
    }
    if (subTotal != (a.length * (a.length*a.length + 1) / 2))
    {
      return false;
    }
    
    colCounter = 0;
    subTotal = 0;
    
    while (colCounter < a.length)
    {
      subTotal = subTotal + a[colCounter][rowCounter];
      colCounter++;
      rowCounter--;    
    }
    if (subTotal != (a.length * (a.length*a.length + 1) / 2))
    {
      return false;
    }
    
    return true;
  }
  private static boolean isOdd(int w)
  {
 
    return (0 != w % 2);
  }
  
  private int wrapAround(int input, int arrayLength)
  {
    return (input + arrayLength) % arrayLength;
  }
  
  
}