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sidd607
 2 years ago
how do you convert a string such as (2+3)*4+(4+5) to a list such as [[2,"+",3],"*",4,"+",[4,"+",5]] and evaluate the value of the expression??
sidd607
 2 years ago
how do you convert a string such as (2+3)*4+(4+5) to a list such as [[2,"+",3],"*",4,"+",[4,"+",5]] and evaluate the value of the expression??

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e.mccormick
 2 years ago
Best ResponseYou've already chosen the best response.0You would need to examine the string using some sort of a loop and find all the parenthesis first. This would allow you to build the order of operations into your evaluation system. In fact, working with the order of operations would be the real key. That would let you place things in the list in the order they need to be evaluated to get an answer. Also, your evaluation routine would need to loop or recurs based on if it finds a list within the list.

A.Avinash_Goutham
 2 years ago
Best ResponseYou've already chosen the best response.0use a stack..

e.mccormick
 2 years ago
Best ResponseYou've already chosen the best response.0@A.Avinash_Goutham He posted in the MIT 6.189 area, which is an Intro to Python class. In Python, the list can be used as a stack. With append() and pop() it becomes a LIFO data structure.

sidd607
 2 years ago
Best ResponseYou've already chosen the best response.0i got the logic. But the problem is i am not being able to write the proper code.

e.mccormick
 2 years ago
Best ResponseYou've already chosen the best response.0Well, what did you come up with?

droopy4096
 2 years ago
Best ResponseYou've already chosen the best response.0@sidd607 , while not my solution, here's what google brings up  http://stackoverflow.com/questions/2371436/evaluatingamathematicalexpressioninastring in other words  there is no simple solution to this as you have to parse numerical strings that can get pretty hairy...

goformit100
 2 years ago
Best ResponseYou've already chosen the best response.0A warm Welcome to OpenStudy. I can help guide you through this useful site. You can ask your questions to me or you can message me. Please use the chat for off topic questions. Remember to give the person who helped you a medal by clicking on "Best Answer". We follow a code of conduct, ( http://openstudy.com/codeofconduct ). Please take a moment to read it.q
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