Flatten Nested List Iterator
Intuition
Solution
#!/usr/bin/env python
# coding=utf-8
#
# Author: Lucas
# Date: 2019-05-27 23:13:12
# """
# This is the interface that allows for creating nested lists.
# You should not implement it, or speculate about its implementation
# """
#class NestedInteger(object):
# def isInteger(self):
# """
# @return True if this NestedInteger holds a single integer, rather than a nested list.
# :rtype bool
# """
#
# def getInteger(self):
# """
# @return the single integer that this NestedInteger holds, if it holds a single integer
# Return None if this NestedInteger holds a nested list
# :rtype int
# """
#
# def getList(self):
# """
# @return the nested list that this NestedInteger holds, if it holds a nested list
# Return None if this NestedInteger holds a single integer
# :rtype List[NestedInteger]
# """
class NestedIterator(object):
def _dfs_init(self, node):
if node.isInteger():
self.data.append(node.getInteger())
else:
for child in node.getList():
self._dfs_init(child)
def __init__(self, nestedList):
"""
Initialize your data structure here.
:type nestedList: List[NestedInteger]
"""
self.data = []
self.index = 0
for node in nestedList:
self._dfs_init(node)
# self._dfs_init(nestedList)
def next(self):
"""
:rtype: int
"""
i = self.index
self.index += 1
return self.data[i]
def hasNext(self):
"""
:rtype: bool
"""
return self.index < len(self.data)
# Your NestedIterator object will be instantiated and called as such:
# i, v = NestedIterator(nestedList), []
# while i.hasNext(): v.append(i.next())