Longest Substring Without Repeating Characters

Longest Substring Without Repeating Characters

LeetCode Problem

• Problem Number: 3
• Problem Link: https://leetcode.com/problems/longest-substring-without-repeating-characters/
• Difficulty: Medium
• Topics: Hash Table, String, Sliding Window

Problem Description

Given a string s, find the length of the longest substring without repeating characters.

Note:

• A substring is a contiguous sequence of characters within the string
• The substring must not have any repeating characters

Examples

Example 1:

Input: s = "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.

Example 2:

Input: s = "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.

Example 3:

Input: s = "pwwkew"
Output: 3
Explanation: The answer is "wke", with the length of 3.
Notice that the answer must be a substring, "pwke" is a subsequence and not a substring.

Constraints

• 0 <= s.length <= 5 * 10⁴
• s consists of English letters, digits, symbols and spaces