That's an entirely valid use of the term. "Algorithm" comes from "al-Khwarizmi", a Persian mathematician from 700-800s. "Euclid's algorithm" is from 300 BC.

In its original conception, "algorithm" just referred to any series of steps one could follow mechanically to reach a solution to a problem. Delegating those mechanical steps to a computer (another word that used to refer to a person!) came much later.

This isn't necessarily a misuse of the word.