Hamming distance

Edit distance, which takes into account only substitute operations.

$$dist_{Ham}(a,b) = \begin{cases} \infty,& \text{if } |a| \neq |b|\\ \sum_{i=0}^{|a| - 1}{a_i \neq b_i},& otherwise \end{cases}$$

Algorithms

	Time complexity	Space complexity
Naive solution1	$O(n)$	$O(n)$

Footnotes

1. string2string: A Modern Python Library for String-to-String Algorithms ↗ ↩