Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1. Example 1: The character 'l' at index 0 is the first character that does not occur at any other …

Apr 7, 2025 · After the string traversal, traverse the visited array and check if value in the array is not equal to -1 or -2 (means, this character is not repeating). We then find the smallest positive index …

Apr 19, 2024 · In this tutorial, we’re going to look at the different ways of finding the first non-repeating character in a String in Java. We’ll also try to analyze the running time complexities of the solutions.

What is the First Non-Repeating Character Problem? The problem is straightforward: given a string, find the first character that appears exactly once. If no such character exists, return a special character …

Find the first non-repeating character in a string and return its index. LeetCodee solution with Python, Java, C++, JavaScript, and C# code examples.

Sep 6, 2025 · In this tutorial, we will write a C program that identifies the first non-repeating character in a string. We will explore different approaches, including using count arrays and pointers.

Write a program to find the first non-repeating character in a string. For example, given the input “swiss”, the output should be “w”, since it’s the first character that doesn’t...

Sep 20, 2025 · For each character in the string, it scans from the beginning to find the first non-repeating character by checking the frequency of each character up to that point. If a non-repeating character …

The first letter that appears only once is ‘w’. This is a common puzzle in programming, and hash tables offer a neat and efficient way to solve it. This article will guide you through how to use a hash table to …

Sep 13, 2025 · Returns the first non-repeating character (if present). Backend developer working with Java, Spring Boot, Microservices, NoSQL, and AWS. I love sharing knowledge, practical tips, and …