Implementing an efficent algorithm to find the intersection of two strings

Question

Implement an algorithm that takes two strings as input, and returns the intersection of the two, with each letter represented at most once.

Answer 1

"with each letter represented at most once"

I'm assuming that this means you just need to know the intersections, and not how many times they occurred. If that's so then you can trim down your algorithm by making use of yield. Instead of storing the count and continuing to iterate the second string looking for additional matches, you can yield the intersection right there and continue to the next possible match from the first string.