package problems.medium;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
/**
* Created by sherxon on 4/30/17.
*/
public class FlattenNestedListIterator {
public class NestedIterator implements Iterator<Integer> {
//List<NestedInteger> list;
LinkedList<NestedInteger> list;
public NestedIterator(List<NestedInteger> nestedList) {
this.list= new LinkedList<>(nestedList);
}
@Override
public Integer next() {
return list.removeFirst().getInteger();
}
NestedInteger getFirstInteger(NestedInteger ni){
if(ni==null || ni.isInteger())return ni;
list.addAll(0, ni.getList());
return getFirstInteger(list.pollFirst());
}
@Override
public boolean hasNext() {
if(list.isEmpty())return false;
if(list.getFirst().isInteger())return true;
NestedInteger n=getFirstInteger(list.pollFirst());
if(n==null)return false;
list.addFirst(n);
return true;
}
}
}