Iterate NestedInteger Contents in Their Original Flattened Order
Company: Amazon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Other
### Problem
Implement `NestedIterator(vector<NestedInteger>&)`, next() and hasNext(). Flatten nested lists in left-to-right depth-first order. The caller repeatedly checks hasNext and then calls next. NestedInteger offers isInteger(), getInteger() and getList(); use these typed accessors and preserve all iterator methods.
```cpp
class NestedIterator {
public:
NestedIterator(vector<NestedInteger> &nestedList);
int next();
bool hasNext();
};
```
### Examples
```text
NestedIterator([[],[2,[3]],4]); repeated hasNext/next yields [2,3,4]
NestedIterator([[]]); hasNext() -> false
```
### Constraints
- The outer nestedList has 1 through 500 elements.
- Integer values lie in [-1000000,1000000].
- No total nested-element or nesting-depth bound is supplied.
Overview: Iterate NestedInteger Contents in Their Original Flattened Order. Implement NestedIterator(vector NestedInteger &), next() and hasNext(). Flatten nested lists in left-to-right depth-first order. The caller repeatedly checks ha
