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[LeetCode] Excel Sheet Column Number (No.171)

Related to question Excel Sheet Column Title

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

For example:

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

Ref: https://leetcode.com/problems/excel-sheet-column-number/

In brief:
This one is basically a sibling of No.168: one converts from the number, and this one converts from the letters. The things to watch out for are similar too.

Approach:
You can likewise get the answer using base-26, but my solution is kind of dumb and therefore not that fast—though not so bad as to TLE. Afterwards I looked up a solution anyway; in the CODE there’s a bestAlgorithm() which is the best solution I’ve found so far.

Partial code:

Full code:
https://github.com/jimc1682000/LeetCode/blob/master/src/answer/ExcelSheetColumnNumber.java

Signed in Taiwan · 2016