The Shunting Yard Algorithm Demystified: Transform Expressions Like a Pro!

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Welcome to my in-depth tutorial on the Shunting Yard Algorithm! 🚂💻 In this video, I unpack and explain this intriguing and useful algorithm. Designed by Edsger Dijkstra, this algorithm is a cornerstone for understanding expression evaluation and conversion, as it converts infix expressions to postfix (or Reverse Polish Notation) expressions.
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Опубликовано:

16 сен 2024

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Комментарии : 30

@rezkamali 13 дней назад

Great explanation! Just a quick point to avoid any confusion: while it's possible to implement the algorithm using two stacks, the original method actually uses one stack and a queue. To clarify, when you use the output list in your code and create the output text using join, it functions as a First-In-First-Out (FIFO) structure, similar to a queue, not like a stack.

@tommurphy7157 6 месяцев назад

Brilliantly explained and very timely! Just what I needed to create the 'advanced' search for my app

@dono42 6 месяцев назад

I used RPN on my HP48G calculator while in high school. I also learned the Shunting Yard algorithm in my Computer Science degree; however, I guess I never really understood what "shunting yard" meant. It seems to be the British expression for a rail yard. I don't think it is a common term in US English. I recall classmates jokingly interpret it as "shatting yard" as in a place to to take shit.

@muddyexport5639 6 месяцев назад

Excellent explanation and demo.

@GaryExplains 6 месяцев назад

Glad you liked it!

@nickeax 4 месяца назад

Thank you for the great presentation.

@user-jv1js9oc8l 6 месяцев назад

This was perfect timing thank you!

@GaryExplains 6 месяцев назад

So glad!

@alejandroguardiola9085 4 месяца назад

Great video, but I have a question, in the explanation it seems like the output is a queue instead of a stack?

@bertblankenstein3738 6 месяцев назад

Once upon a time I coded a stack and the operators were numbers in an array of pointers to functions. I was kind of hoping to learn how this relates to railyards tho.

@kenc4026 4 месяца назад

Great work, sir. I got an idea because of this. Does this logic applies to Boolean Algebra too?

@cxrbon637 4 месяца назад

i think so

@Garythefireman66 6 месяцев назад

Thanks professor! 🤓

@GaryExplains 6 месяцев назад

My pleasure!

@AlwaysCensored-xp1be 6 месяцев назад

I wonder if LLM can solve those model train shunting games?

@berjancemdarc4345 4 месяца назад

What would this code do on situations like 10+2 ?

@Lumelore 2 месяца назад

When it parses the input it uses space as a delimiter, so 10 would be interpreted as 10 but 1 0 would be two separate entries. In the stack, 10 is stored as a single element and not multiple separate ones for each digit.

@HyyskanPolttaja 6 месяцев назад

Great! But what about square roots & stuff?

@GaryExplains 6 месяцев назад

For other operations you would use functions like cos (), sqrt(), etc. This is how you could write a compiler or interpreter using this method. It is the same principle. Functions have a lower precedence than plus and minus. Raise-to-power ^ has the highest precedence.

@uvatham 6 месяцев назад

00:06

@GaryExplains 6 месяцев назад

🚂

@jameslewis7620 5 месяцев назад

🤣

@K9-33 6 месяцев назад

Just use the FORTH programming language.

@GaryExplains 6 месяцев назад

That isn't the point. The point is to know how to do it yourself.

@sssyt4837 6 месяцев назад

First!

@LA-MJ 6 месяцев назад

Exit takes an exit code not a calculation result 😂

@GaryExplains 6 месяцев назад

And why can't the exit code be a calculation result?

@LA-MJ 6 месяцев назад

@@GaryExplainsbecause non-zero exit code means error occurred in standard semantics

@GaryExplains 6 месяцев назад

No, not necessarily. If you want a program to calculate something it can return the calculation as an exit code. This is very useful for scripting. You are making an assumption about the return codes, I assume based on Unix/Linux. On VMS for example SUCCESS was never 0.

@LA-MJ 5 месяцев назад

@@GaryExplainsof course it's UNIX. Which matters more