Sunbound | Senior Frontend Software Engineer (Senior) | Coding | Phone Screen

Given a buffer of random lowercase letters. Identify the first position where the four most recently received characters were all different. Specifically, it needs to report the number of characters from the beginning of the buffer to the end of the first such four character marker. Examples: bvwbjplbgvbhsrlpgdmjqwftvncz: first marker after character 5 nppdvjthqldpwncqszvftbrmjlhg: first marker after character 6 nznr...