Let’s say I have three words I want to sort:
- hello
- goodbye
- alex
And alphabetically it’d be sorted ascendingly as ["alex", "goodbye", "hello"]. Is there a way to convert the string (limited to 100 characters)? For example, if I have:
['a', 'l', 'e', 'x']
And I use ord to get the code for each list-element:
[1, 12, 5, 24]
How would I create a number from that, that would also be smaller than, say, goodbye ?
>Solution :
Use:
from operator import mul, pow
from itertools import repeat
LIMIT = 100
char_vals = [1, 12, 5, 24]
sum(map(mul, char_vals, map(pow, repeat(27), range(LIMIT, 0, -1))))
Since you’ve bounded the length of the strings, you can think of each word as a base-27 number. 0 represents that the letter doesn’t exist, 1 represents a, 2 represents b, etc.
Then, the numerical value of each word can be computed using the following polynomial:
i_1 * 27**100 + i_2 * 27**99 + ...
where char_vals = [i_1, i_2, ...] (i.e. each i is the integer value of the corresponding letter).