Flatten Nested List Iterator

Problem: Flatten Nested List Iterator You are given a nested list of integers nestedList. Each element is either an integer or a list whose elements may also be integers or lists. The nesting depth is arbitrary. Implement an iterator that returns all integers in left-to-right order. You need to support two operations: next(): return the next integer. hasNext(): return true if there is a next integer; otherwise return false. In the interview, you may be asked to: Implement it recursively first; Then implement it using an explicit stack, avoiding full recursive flattening upfront. Input/Output for Testing For convenient testing, the input is a JSON-style nested array, and the output is the flattened integer array. Constraints Total number of integers n: 0 <= n <= 10^5. Maximum nesting depth: 10^4. Integer range: [-10^9, 10^9]. Example Input: [[1,1],2,[1,1]] Output: [1, 1, 2, 1, 1] Example Input [[1,1],2,[1,1]] Output [1, 1, 2, 1, 1]