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Blind 75 Difficulty: Easy Difficulty: Medium Difficulty: Hard

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UUID Generator Code Formatter

First Unique Character in a Stream of Characters

Last edited: August 2, 2025

Problem
Examples
Solution
Method 1 - Using Queue and Hashmap
Algorithm
Dry Run
Code
Complexity
Method 2 - Using DLL (Doubly Linked List) and Hashmap
Algorithm
Dry Run
Complexity
Method 3 - Using LinkedHashSet for DLL and HashSet for Boolean Array
Complexity

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