Adding code for issue #388.

[venkatsgithub1]

Solution for Longest substring with distinct characters.

Issue Id you have worked upon -

issue #388

Briefly explain your program logic -

The solution uses sliding window mechanism to maintain a window start, window end and uses a map to see if distinct characters are being used for max length of substring.

Screenshots(Attach 2 screenshots of your own input and output) -

Attach here Input: Output:

Checklist:

Eg - If your code follow the below guidelines. Kindly change [] to [x]

All the conditions should be fulfilled for considering your code for merging -

• [x] I have mentioned the question as comment in my solution file.
  

• [x] My code follows the guidelines of this project.
  

• [x] I have performed a self-review of my own code.
  

• [x] I have commented my code.
  

• [x] My code gives the correct output.
  

• [x] I confirm that I have not copied the code from anywhere. In case its found that I have copied even after successful merge then I can be banned from the repository and hacktoberfest.
  

• [x] I affirm that I strictly follow contributing guidelines and code of conduct.

[venkatsgithub1]

@SarthakKeshari - Added solution for issue #388