Remove Duplicates from String Problem Statement

You are provided a string STR of length N, consisting solely of lowercase English letters.

Your task is to remove all duplicate occurrences of characters in the string.

Example:

Input:

abcadeecfb

Output:

abcdef

Explanation:

After removing duplicates, the string becomes abcdef.

Constraints:

• 1 ≤ N <= 4*10^5
• Time Limit: 1 sec