168. Excel Sheet Column Title returns the title of excel by numbers

[copy title]:

Given a positive integer, return its corresponding column title as appear in an Excel sheet.

For example:

    1 -> A
    2 -> B
    3 -> C
    ...
    26 -> Z
    27 -> AA
    28 -> AB
    ...

Example 1:

Input: 1
Output: "A"

Example 2:

Input: 28
Output: "AB"

Example 3:

Input: 701
Output: "ZY"

 [brute force solution]:

Time analysis:

Space Analysis:

 [Optimized]:

Time analysis:

Space Analysis:

[Wonderful output conditions]:

[Wonderful corner case]:

[Thinking question]:

[One sentence idea]:

[Input amount]: Empty: Normal situation: Extra large: Extra small: Special situations handled in the program: Abnormal situations (Illegal and unreasonable input):

[Paint]:

[One brush]:

[Second brush]:

[Three brushes]:

[Four brushes]:

[Five brushes]:

  [Results of five-minute naked eye debug]:

[Summarize]:

[Complexity]: Time complexity: O( ) Space complexity: O( )

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

[Key templating code]:

[Other solutions]:

［Follow Up］：

[The topics given by LC change and change]:

 [Code style]: