Longest Substring Without Repeating Characters - Leetcode 3 - Python

Title: Longest Substring Without Repeating Characters - Leetcode 3 - Python

Step-by-Step Tutorial:

1. Understand the problem: The goal is to find the longest substring in a given string without any repeating characters.

2. Initialize two pointers, a left pointer, and a right pointer to determine the sliding window. Set the left pointer to 0.

3. Iterate through each character in the string using a for loop with the right pointer.

4. Check if the character at the right pointer is already in the character set (indicating a duplicate).

5. If a duplicate is found, remove the leftmost character from the set and increment the left pointer until the duplicate character is no longer in the set.

6. Add the rightmost character to the set.

7. Update the result variable to store the length of the current window if it is larger than the previous result. Calculate the window size using right pointer - left pointer + 1.

8. Continue iterating through the string until all characters have been processed.

9. Return the result, which represents the length of the longest substring without repeating characters.

10. Implement the sliding window technique to efficiently find the longest substring without repeating characters.

11. Use a set to store unique characters and check for duplicates instantly.

12. By shrinking and expanding the window based on duplicate characters, ensure that the substring does not contain any repeating characters.

13. Update the result variable as needed to keep track of the longest substring found.

14. Once the entire string is processed, return the final result as the length of the longest substring without repeating characters.

15. Remember to handle edge cases and ensure the algorithm works correctly for different input strings.

16. Test the algorithm with different strings to verify its correctness and efficiency.

17. Optimize the algorithm to achieve a time complexity of O(n) by using the sliding window technique and set data structure.

18. Consider potential improvements or modifications based on specific requirements or constraints of the problem.

19. Further optimize the code if needed to enhance performance or readability.

20. If you found this tutorial helpful, consider leaving a like and subscribing to the channel for more content. Thank you for watching!