[Leetcode] Flatten Nested List Iterator

Given a nested list of integers, implement an iterator to flatten it.

Each element was either an integer, or a list–whose elements could also be integers or other lists.

Example 1:
Given the list [[1,1],2,[1,1]] ,

By calling next repeatedly until Hasnext returns false, the order of elements returned by next should is: [1,1,2,1,1] .

Example 2:
Given the list [1,[4,[6]]] ,

By calling next repeatedly until Hasnext returns false, the order of elements returned by next should is: [1,4,6] .

Thinking of solving problems

First, the integer element is recursively grouped into a list, and then traversed by a list of iterators.

Implementation code

//Runtime:6 MS/** *//This was the interface that allows for creating nested lists. *//You should not implement it, or speculate a Bout its implementation * public interface Nestedinteger {* *// @return True if this nestedinteger holds a Single integer, rather than a nested list. * Public boolean isinteger ();  * *// @return The single integer Nestedinteger holds, if it holds a single integer *//return Null if this nestedinteger holds a nested list * public Integer getinteger (); * *// @return The nested list that this nestedinteger holds, if it holds a nested list *//return NULL If this nestedinteger holds a single integer * Public list<nestedinteger> getList (); * } */ Public  class nestediterator implements Iterator<Integer> {    PrivateList<integer> nums =NewArraylist<> ();PrivateIterator<integer> Iterator =NULL; Public Nestediterator(list<nestedinteger> nestedlist) { for(Nestedinteger nestedinteger:nestedlist)        {Addnestedinteger (Nestedinteger);    } iterator = Nums.iterator (); }@Override     PublicIntegerNext() {returnIterator.next (); }@Override     Public Boolean Hasnext() {returnIterator.hasnext (); }Private void Addnestedinteger(Nestedinteger Nestedinteger) {if(Nestedinteger.isinteger ())        {Nums.add (Nestedinteger.getinteger ()); }Else{list<nestedinteger> nestedlist = nestedinteger.getlist (); for(Nestedinteger nested:nestedlist)            {Addnestedinteger (nested); }        }    }}/** * Your Nestediterator object would be instantiated and called as such: * nestediterator i = new Nestediterator (nest Edlist); * while (I.hasnext ()) v[f ()] = I.next (); */

[Leetcode] Flatten Nested List Iterator