The 5 String Interview Patterns You Need to Know

String interview questions are some of the most common interview questions out there. And most people skip them because they think string problems are easy.

But they can be deceptively complex.

If you don't take the time to master string interview questions, you are potentially setting yourself up for failure.

In this video, I go through the 5 most important patterns that you need to understand to master the string interview. With these, you'll be able to solve almost any string problem and be fully prepared for your interview.

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[venkatakallagunta]

1 . Use integer array of length 256 to represent character counts(1:17) Ex: If two strings are palindromes
2. Using two pointers in a string(2:52) Ex: Reverse a string
3. Do string math, how to convert string between characters, integers(3:55)
4. Using two pointers when comparing two strings. (5:25) Ex: Longest subsequence in two strings, Edit Distance
5. String algorithms in general. Understand the strategies used in general string algorithms.(6:30)

[palakjadav]

The content is great! One tip for making the representation better: Auto-show the examples on the screen while you continue to talk. This is help the student visualize the example and absorb/understand it quicker.

[chenmargalit]

Hey man, thanks for the work ! I've noticed u moved from code/screen videos to just talking. I imagine u have ur reasons, but just so u'll know - I got MUCH more value than now. Not because of the length difference, but cause its very useful to actually see and not only hear, when talking about complicated stuff.

[TheGianaJinx]

I love these videos. I feel much less anxious learning the "tricks" and patterns rather than trying to memorize everything ever.

[truthM]

Thanks for the tips Sam... They are as always to the Point 🙏

[david_ramoraswi]

this is immensely helpful as i am preparing for my interview. Thank you buddy

[atift]

Just came across your channel. Love your explanations and all your vids. Subscribed!

[libitard]

This is really great suggestions. This is greatly appreciated. I downloaded my guide. Thank you so much.

[RandomGuy-prgt]

Having gone through these, what Sam shared are valuable tips.

[ganeshpreetham]

Thanks for the awesome video mate. This is really helpful

[hitec]

Nice Video. In case of Java we prefer string for the key in HashMap as its hash is only calculated once and then cached in String pool. Strings are immutable in java.

[chetankadam]

Thanks for giving me this method to practice analyse large number of problems into types...

[mohdfayaq]

Never thought string lookups in hashtable wouldn't be constant, thanks alot!

[umeshbaku]

Hello Sam, I am the new subscriber here. Just loved how you focused on these patterns. Could please do the same for outlining the tree? I will really appreciate that. Thanks for this great video.

[cocoarecords]

ADT patterns you need to know series? would be very beneficial and uniqiue !

[hondaboy]

Awesome. Hopefully there are other 'pattern' videos in the works.

[jasonrodriguez]

Very good video. Thank you for your content. Everytime you say "we" in your intro portion it makes me think you have multiple personalities lol.

[batlin]

For the "integer array of character counts", you mentioned Unicode, and it's probably worth asking the interviewer if they want to handle that. There's over 1 million Unicode code points, so that having an array of 1 million integers could be more overhead than using a hashmap, especially in a language with boxed ints, or if the input string only uses a small range of characters. I just checked in Python and on my machine an array with (17*65536) zeroes takes about 9 MB.
If it's a whiteboard problem then they probably don't care, though.

[juliahuanlingtong]

From end work backwards tecnique is often used. How to identify such problem when used in array and string?

[codeblooded]

Isnt using hashtable or array will lead to same time complexity? Infact if we have Then hashtable will hold less space