I was recently asked in a job interview to resolve a programming puzzle that I thought it would be interesting to share. It's about translating Excel column letters to actual numbers, if you recall, Excel names its columns with letters from A to Z, and then the sequence goes AA, AB, AC... AZ, BA, BB, etc.
You have to write a function that accepts a string as a parameter (like "AABCCE") and returns the actual column number.
The solution can be in any language.
I wrote this ages ago for some Python script:
def index_to_int(index):
s = 0
pow = 1
for letter in index[::-1]:
d = int(letter,36) - 9
s += pow * d
pow *= 26
# excel starts column numeration from 1
return s