Write a method named spiral 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 in the order they would appear if visited in a "spiral" order, clockwise starting from top-left.
For example, if the given 2-D array is declared:
int[][] matrix = {
{ 1, 2, 3, 4, 5},
{ 6, 7, 8, 9, 10},
{11, 12, 13, 14, 15},
{16, 17, 18, 19, 20},
};
Then the call of spiral(matrix) should return the following 1-D array:
{1, 2, 3, 4, 5, 10, 15, 20, 19, 18, 17, 16, 11, 6, 7, 8, 9, 14, 13, 12}
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.
You may also assume that the 2-D array contains at least one row and column.
Your method should not modify the array that is passed in.
