First Non-Repeating Character
August 19, 2011
This question appears on several lists of interview questions:
Write a function that takes an input string and returns the first character from the string that is not repeated later in the string. For instance, the two letters “d” and “f” in the input string “aabcbcdeef” are non-repeating, and the function should return “d” since “f” appears later in the string. The function should return some indication if there are no non-repeating characters in the string.
Your task is to write the indicated function. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.
Programming Praxis 