First Unique Character in a String Problem Statement

Given a string STR consisting of lowercase English letters, identify the first non-repeating character in the string and return it. If no such character exists, return '#'.

Input:

The first line consists of an integer T representing the number of test cases.
For each test case, there is a single line consisting of a string STR containing only lowercase English letters.

Output:

For each test case, output the first non-repeating character in the given string.
Output each result on a new line.

Example:

Input:

2
abcab
aabbcc

Output:

c
#

Explanation:

For the first test case, 'c' is the first non-repeating character in 'abcab'.
For the second test case, there is no non-repeating character in 'aabbcc', hence the output is '#'.

Constraints:

• 1 <= T <= 100
• 1 <= N <= 10^4

Where T denotes the number of test cases, and N represents the length of the string. The time limit for each test case process is 1 second.

Note:

No need to print anything; just implement the function to return the result.