281.py

'''
Given two 1d vectors, implement an iterator to return their elements alternately.

For example, given two 1d vectors:

v1 = [1, 2]
v2 = [3, 4, 5, 6]
By calling next repeatedly until hasNext returns false, the order of elements returned by next should be: [1, 3, 2, 4, 5, 6].
'''

classSolution(object):
def__init__(self, v1, v2):
self.v1=v1
self.v2=v2
self.index_v1=0
self.index_v2=0

defnext(self):
result=-1
ifself.index_v1!=len(self.v1) andself.index_v1<=self.index_v2:
result=self.v1[self.index_v1]
self.index_v1+=1
else:
result=self.v2[self.index_v2]
self.index_v2+=1

returnresult

defhasNext(self):
returnself.index_v1<len(self.v1) orself.index_v2<len(self.v2)


solution=Solution([1, 2], [3, 4, 5, 6])
whilesolution.hasNext():
printsolution.next()