Problem 44382. Parse me a Lisp

Created by @bmtran (Bryant Tran)

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294 Solutions
111 Solvers

Last Solution submitted on Aug 19, 2020

Last 200 Solutions

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3 Comments

3 Comments

Alfonso Nieto-Castanon on 19 Oct 2017

it seems look-up table solutions are becoming a bit of an issue, could you please add a few test cases to discourage this? +1 for random test cases that are a bit harder to trick, for example something like n=randi(100,1,randi(10)); expr = "(+" + string(num2str(n))+ ")"; assert(isequal(eval_lisp(expr), sum(n)));

James on 11 Dec 2017

I think another test case with multiple expressions would be equally useful. Even something as simple as (+ 1 (* 2 3) 4) would prevent some of the look-up solutions. Make some of those values random, and it will work even better.

Rafael S.T. Vieira on 8 Jul 2020

Good problem, and better than 44374. Precedence is clear.

Solution Comments

Solution 2251131

1 Comment

1 Comment

Alex Pedcenko on 8 May 2020

cheat

Solution 1312667

1 Comment

1 Comment

James on 11 Dec 2017

Nice. I was trying to figure out how to use strtok, but couldn't quite come up with it.

Solution 1292106

3 Comments

3 Comments

T. Dunker on 17 Oct 2017

Are you sure that your Test Suite works? I had to change all the double quotes to single quotes.

@bmtran (Bryant Tran) on 18 Oct 2017

Double-quoted strings are string literals in MATLAB R2017a+. To convert a string to char array, use the "char" function.

James on 11 Dec 2017

Thank you for that hint about the "char", bmtran. Never would have figured out what was wrong with my solution otherwise...

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Problem 44382. Parse me a Lisp

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Problem 44382. Parse me a Lisp

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