Data Structures and Algorithms
with Object-Oriented Design Patterns in Java 
The simplest way to implement a matrix is to use an array
of arrays as shown in Program 
.
In this case, we use three fields.
The first two fields, numberOfRows and numberOfColumns
record the dimensions of the matrix.
The third field, array,
is a Java array of arrays of doubles.
Program: DenseMatrix fields and constructor.
The constructor takes two arguments, m and n,
and constructs the corresponding 
matrix.
Clearly, the running time of the constructor is O(mn).
(Remember, Java initializes all the array elements to zero).
Copyright © 1998 by Bruno R. Preiss, P.Eng. All rights reserved.