# 341. Flatten Nested List iterator Expand multilayer arrays

Source: Internet
Author: User

[Copy question]:

Given a nested list of integers, implement an iterator to flatten it.

Each element was either an integer, or a list--whose elements may also be integers or other lists.

Example 1:
Given the list `[[1,1],2,[1,1]]` ,

By calling next repeatedly until hasnext returns FALSE, the order of elements returned by next should be: `[1,1,2,1,1]` .

Example 2:
Given the list `[1,[4,[6]]]` ,

By calling next repeatedly until hasnext returns FALSE, the order of elements returned by next should be: `[1,4,6]` .

[Brute force solution]:

Time Analysis:

Spatial Analysis:

[After optimization]:

Time Analysis:

Spatial Analysis:

[Wonderful output CONDITIONS]:

[Wonderful corner case]:

[Thinking questions]:

Don't know what the difference is between next and. Hasnext: Take it out and just see if there's

[a sentence of thought]:

[input]: null: Normal: Large: Extra Small: Special cases handled in the program: abnormal conditions (unreasonable input):

[Drawing]:

[One brush]:

[Two brushes]:

[Three brushes]:

[Four brushes]:

[Five brushes]:

[Results of five-minute visual debug]:

[Summary]:

[Complexity]:time Complexity:o () Space complexity:o ()

[English data structure or algorithm, why not other data structures or algorithms]:

Only the stack can be removed one layer at a time, and the array cannot be removed directly from one layer. So use stack.

Stack has

``.getInteger()``
``.getList()``

Method

[Algorithmic thinking: Recursion/division/greed]:

[Key templating code]:

[Other solutions]:

[The problem given by the LC becomes variable]:

[Code Style]:

341. Flatten Nested List iterator Expand multilayer arrays

Related Keywords:

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