/*
 * Matrix addition - complete the add method below
 *                   see expected output at end
 * @author
 */
 
public class Matrix {

  //Return true if matrix is "ragged", ie. not all rows
  //have the same number of values (columns)
  //false otherwise
  public static boolean isRagged(int[][] matrix) {
    if (matrix.length == 0)
      return false;
    int cols = matrix[0].length;
    for (int i = 1; i < matrix.length; i++)
      if (matrix[i].length != cols)
        return true;
    return false;
  }

  //Output the matrix values one row per line
  public static void output(int[][] matrix) {
    for (int i = 0; i < matrix.length; i++) {
      for (int j = 0; j < matrix[i].length; j++) {
        if (matrix[i][j] < 10)
          System.out.print("  " + matrix[i][j]);
	else
	  System.out.print(" " + matrix[i][j]);
       }
       System.out.println();
     }
   }
   
   //Return a matrix that is the sum of m1 and m2
   //if m1 and m2 have the same number of rows and
   //cols and are not "ragged" or empty
   //otherwise return null
   public static int[][] add(int[][] m1, int[][] m2) {
     
     
     
     
   }
   
   public static void main(String[] args) {
   
     int[][] matrix1 = {{1, 2, 3},
                        {4, 5, 6}};
		   
     int[][] matrix2 = {{9, 3, 5},
                        {0, 3, 8}};
			
     int[][] matrix3 = {{1, 4},
                        {2, 3, 5},
			{4}};
		
      System.out.println("\nMatrix 1: ");
      output(matrix1);
      
      System.out.println("\nMatrix 2: ");
      output(matrix2);
      
      System.out.println("\nMatrix 3(not really a \"matrix\"): ");
      output(matrix3);
      
      System.out.println("\nMatrix 1 is ragged: " + isRagged(matrix1));
      
      System.out.println("\nMatrix 3 is ragged: " + isRagged(matrix3));
      
      int[][] sum = add(matrix1, matrix2);
      System.out.println("\nMatrix 1 + Matrix 2: " );
      
      output(sum);
   }
}
/*
eos% java Matrix

Matrix 1: 
  1  2  3
  4  5  6

Matrix 2: 
  9  3  5
  0  3  8

Matrix 3(not really a "matrix"): 
  1  4
  2  3  5
  4

Matrix 1 is ragged: false

Matrix 3 is ragged: true

Matrix 1 + Matrix 2: 
 10  5  8
  4  8 14
*/