Flatten N-Dimensional Array to 1D Array

You are given an N-dimensional array (a nested list) and your task is to convert it into a 1D array. The N-dimensional array can have any number of nested lists and each nested list can contain any number of elements. The elements in the nested lists are integers. Write a function that takes an N-dimensional array as input and returns a 1D array.

Example 1:

Input:

array = [1, [2, 3], [4, [5, 6]], 7]

Output:

flatten_array(array) -> [1, 2, 3, 4, 5, 6, 7]

Example 2:

Input:

array = [[1, 2], [3, 4], [5, 6]]

Output:

flatten_array(array) -> [1, 2, 3, 4, 5, 6]