leetcode-284-顶端迭代器

题目描述：

class PeekingIterator:     def __init__(self, iterator):         """         Initialize your data structure here.         :type iterator: Iterator         """         self.iterator = iterator         self.pre = None      def peek(self):         """         Returns the next element in the iteration without advancing the iterator.         :rtype: int         """         if self.pre:             return self.pre         self.pre = self.iterator.next()         return self.pre      def next(self):         """         :rtype: int         """         if self.pre:             num = self.pre             self.pre = None             return num         return self.iterator.next()               def hasNext(self):         """         :rtype: bool         """         if self.pre:             return True         if self.iterator.hasNext():             return True         return False

来源：博客园

作者：真不知道叫啥好

链接：https://www.cnblogs.com/oldby/p/11684278.html