In this challenge, we will check if a string contains consecutive letters as they appear in the English alphabet and if each letter occurs only once.

Rules are: (1) the letters are adjacent in the English alphabet, and (2) each letter occurs only once.

For example:
solve("abc") = True, because it contains a,b,c
solve("abd") = False, because a, b, d are not consecutive/adjacent in the alphabet, and c is missing.
solve("dabc") = True, because it contains a, b, c, d
solve("abbc") = False, because b does not occur once.
solve("v") = True
All inputs will be lowercase letters.

Tests

solve("abc")
solve("zyx")
solve("azj")

Good luck!

This challenge comes from KenKemau on CodeWars. Thank you to CodeWars, who has licensed redistribution of this challenge under the 2-Clause BSD License!

Want to propose a challenge idea for a future post? Email yo+challenge@dev.to with your suggestions!