Find the first unique character in a given string or an array
Problem
You are given an a string of characters including duplicates. You need to find the first non-repeating / unique character.
input: foobar output: f input: aabbccdef output: d input: aabbcc output: 'No Unique Character Found'
Solution
- We will iterate over the string and create a frequency array. Note, not a map.
- This will be a unique array in the sense that the index will be determined based on the input character.
- Iterate over the input string again and look up the value associated with the character index.
- Return the first character whose value is 1.