LeetCode_341扁平化嵌套列表迭代器

给定一个嵌套的整型列表。设计一个迭代器，使其能够遍历这个整型列表中的所有整数。

列表中的项或者为一个整数，或者是另一个列表。

/**
 * // This is the interface that allows for creating nested lists.
 * // You should not implement it, or speculate about 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 that this 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> {

    List<Integer> list;
    Iterator<Integer> iterator;

    public NestedIterator(List<NestedInteger> nestedList) {
        list = new LinkedList<Integer>();
        add(nestedList,list);
        iterator = list.iterator();
    }

    @Override
    public Integer next() {
        return iterator.next();
    }

    @Override
    public boolean hasNext() {
        return iterator.hasNext();
    }

    public void add(List<NestedInteger> nestedList, List<Integer> list){
        for(NestedInteger nest : nestedList){
            if(nest.isInteger()){
                list.add(nest.getInteger());
            }else{
                add(nest.getList(),list);
            }
        }
    }
}

/**
 * Your NestedIterator object will be instantiated and called as such:
 * NestedIterator i = new NestedIterator(nestedList);
 * while (i.hasNext()) v[f()] = i.next();
 */

来源：CSDN

作者：皓月v

链接：https://blog.csdn.net/qq_36198826/article/details/104011224