Stacks are ESSENTIAL for Coding Interviews! | Valid Parentheses - Leetcode 20

leetcode, coding interview question, data structures, data structures and algorithms, faang

[GregHogg]

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[kareem_]

Just found this channel and it's like I stumbled onto a gold mine. Thank you for your videos!!

[parkourninja]

Oooo, clever. I just oearned the stack at the hardware level implementation and sort of loss sight of what it's good for.

[homieinthesky]

I would use a 2 pointer solution. Using the same dictionary.

[Techy]

What about using this (pseudocode):

Function checkValidity():

-For loop for the length of the string
-- replace (), {}, [] with '"" in the original string
-Loop around
-Return string == ""

[AndrewTSq]

Never gotten a question about this, but I made a lexer once, that could be used for this.

[snake]

What is this supposed to achieve in bigger projects?

[speakingsarcasm]

I have another idea. Take three variables v1, v2, v3... When you encounter open paranthesis, increment v1 by 1 and also, decrement by 1 if it's a closed parenthesis... If the value of v1 ever becomes negative, it's invalid... Like wise do for curly braces and second brackets.

[burhancerit-vk]

I have an idea we can solve without a stack as well, just only one parameter number enough.

[Vichion]

Essential for an interview sure...


But what is the practical application? 🙃

[harrimahlstrom]

Got this asked during an Interview for Microsoft 😅

[dashdg]

I’m not the greatest coder so patience with my dumb question, is this faster than comparing the first to the last. Then second to second to last and so on?

[Fly_The_Sky]

Stuff like this, is why NO ONE wants to work for these companies. Awesome, you can do random stuff. Thanks.

[robertsandiford]

What kind of mental desease do you have to have to write your dict like that?

[grandmakisses]

A PDA lol, did you know that a PDA corresponds to a context free grammar which would equal S-> epsilon | S(S)