Given a string S consisting of lowercase Latin Letters. Return the first non-repeating character in S. If there is no non-repeating character, return '$'.
Example 1:
Input:
S = hello
Output: h
Explanation: In the given string, the
first character which is non-repeating
is h, as it appears first and there is
no other 'h' in the string.
Example 2:
Input:
S = zxvczbtxyzvy
Output: c
Explanation: In the given string, 'c' is
the character which is non-repeating.
Your Task:
You only need to complete the function nonrepeatingCharacter() that takes string S as a parameter and returns the character. If there is no non-repeating character then return '$' .
Expected Time Complexity: O(N).
Expected Auxiliary Space: O(Number of distinct characters).
Note: N = |S|
Constraints:
1 <= N <= 10^{3}

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