The Array2DMultiples class contains two static methods that work with two-dimensional arrays.

Part A — buildMatrix

The first method, buildMatrix, constructs and returns a two-dimensional array.

Parameters

• arr : a one-dimensional array of integers
• cols : the number of columns for the two-dimensional array

Rules

• The length of arr determines the number of rows.
• The value of cols determines the number of columns.
• Each row of the 2D array contains the multiples of the corresponding value in arr.

Example

Given:

int[]arr = {7,6,2,6};
int cols =5;

The resulting array will have:

• 4 rows
• 5 columns

Row 0 (multiples of 7):  7   14   21   28   35
Row 1 (multiples of 6):  6   12   18   24   30
Row 2 (multiples of 2):  2    4    6    8   10
Row 3 (multiples of 6):  6   12   18   24   30

Method Header

/**
 * Builds a two-dimensional array using the length of arr as the number of rows
 * and cols as the number of columns.
 *
 * @param arr the array containing the base values
 * @param cols the number of columns in the resulting matrix
 * @precondition arr.length > 0, cols > 0
 * @postcondition returns the constructed two-dimensional array
 */
 
 
publicstaticint[][]buildMatrix(int[]arr,intcols)
{
/* implementation not shown */
}