In this exercise, you'll be given a string with many repeated characters, like
"aaaaaaabbbbbbaaaa" (for example), wherein a repeated character is any character followed by
itself one or more times, with nothing in-between.
Thus, aaaa has "a" as a repeated character, whereas aba does not have a repeated character
(even though the a appears more than once).
Your task is to write a method (complete with an algorithm!) that finds the first non-repeated character in a string, and then returns that character. Here are some examples:
- Given
"aaabbbc"(where"c"is the first non-repeated character), your method should return"c" - Given
"abbccddee"(where"a"is your first non-repeated character), your method should return"a" - Given
"aaabcccd"(where"b"and"d"are both repeated, but"b"comes first), your method should return"b" - Given
"abcde"(where no characters are repeated), your method should return"a"(since it's first) - Given
"aabbcc"(where there are no non-repeated characters), your method should returnnil