Write a method named flatten that accepts a 2-D array of integers as a parameter and that returns a 1-D array with the contents of the original 2-D array "flattened" into a one-dimensional array.
For example, if the given 2-D array is declared:
int[][] matrix = {
{ 3, 8, 12},
{ 2, 9, 17},
{ 43, -8, 46},
{203, 14, 97}
};
Then the call of flatten(matrix) should return the following 1-D array:
{3, 8, 12, 2, 9, 17, 43, -8, 46, 203, 14, 97}
Your code should work for an array of any size, even one with 0 rows or columns.
You may assume that the 2-D array is rectangular, that is, that each row of the 2-D array contains the same number of columns.
Your method should not modify the array that is passed in.
