Isomorphic Substring Problem W2D4-B in Pairboarding Problems Directory Should be O(1) not O(n)

[ckane30691]

https://github.com/appacademy/graduated-job_seeker-program/blob/master/pairboarding-problems/w2d4-b.md
The hashmap in this solution will be bounded by the fact that there are only 26 letters in the alphabet, 10 numbers, and some number of symbols meaning that in this case we can say that the map is O(1). You can imagine that even if we had a string with 1 million characters, our hashmap will not grow linearly to 1 million entries as their will only be so many unique keys before you start overwriting existing keys or in the case that the values don't match you'll return from the function early.