Solution: Longest Substring without Repeating Characters
Explore the sliding window technique to solve the problem of finding the longest substring without repeating characters in a string. Understand how to use a hash map to track character indices and dynamically adjust the window boundaries for optimal time and space complexity. By the end of this lesson, you'll be able to implement a linear time solution that efficiently handles duplicates and calculates the longest unique substring length.
Statement
Given a string, str, return the length of the longest substring without repeating characters.
Constraints:
-
str.length strconsists of English letters, digits, symbols, and spaces.
Solution
So far, you’ve probably brainstormed some approaches on how to solve this problem. Let’s explore some of these approaches and figure out which one to follow while considering time complexity and any implementation constraints.
Naive approach
The naive approach is to explore all possible substrings. For each substring, we check whether any character in it is repeated. After checking all the possible substrings, the substring with the longest length that satisfies the specified condition is returned.
The total time complexity of this solution is ...