dsa · easy
Excel Sheet Column Title
The reverse of Excel column numbering: given a 1-based column_number, return its uppercase title. 1 is "A", 26 is "Z", 27 is "AA". This is base 26 with no zero digit, so you subtract one before each remainder.
Arguments
column_number— 1-based Excel column index to encode as a title
Example
1 → "A".
28 → "AB".
701 → "ZY".
Constraints
1 <= column_number <= 2^31 - 1
Examples
Example 1
Input: 1 Expected: A
Example 2
Input: 28 Expected: AB
Example 3
Input: 701 Expected: ZY