Given a nested list of integers, where each element is either an integer or a list (which may contain integers or other lists), implement a class IntegerListIterator that flattens the nested structure and iterates through all integers in order. The class must support the following methods:
- IntegerListIterator(nested_integer_list): Initializes the iterator with the nested list.
- next(): Returns the next integer in the flattened list.
- has_next(): Returns True if there are more integers to iterate, otherwise False.
The nested list is represented as a list of integers or lists, e.g., [1, [2, [3, 4]], 5].
To test, repeatedly call next() while has_next() is True, collecting the results into a list. The final list should match the fully flattened list of integers.
Example 1
Input: nested_integer_list = [[3,2],5,[7,[8,9]]]
Output: [3,2,5,7,8,9]
Explanation: Flattened order is [3,2,5,7,8,9].
Example 2
Input: nested_integer_list = [10,[20,[30,40]],50]
Output: [10,20,30,40,50]
Explanation: Flattened order is [10,20,30,40,50].
Example 3
Input: nested_integer_list = [[-1,-2],[-3],[-4,[-5]]]
Output: [-1,-2,-3,-4,-5]
Explanation: Flattened order is [-1,-2,-3,-4,-5].
Constraints
Case 1
Input: nested_integer_list = [[0],[1,[2,3]],4]
Expected: [0,1,2,3,4]
Case 2
Input: nested_integer_list = [[],[5],[[6,7]],8]
Expected: [5,6,7,8]
Case 3
Input: nested_integer_list = [100, [200, [300, [400]]]]
Expected: [100,200,300,400]