1 class PeekingIterator: 2 def __init__(self, iterator): 3 self.iterator = iterator 4 self.head = iterator.next() 5 6 def peek(self): 7 return self.head 8 9 def next(self): 10 res = self.head 11 self.head = self.iterator.next() if self.iterator.hasNext() else None 12 return res 13 14 def hasNext(self): 15 return self.head != None
题目类型:设计题,实现迭代器相关功能。