*DAILY CHALLENGE* : write a code that gets as input a mathematical string and calculate its result!

Question

INFO:
The string can contain following characters:
- '0'..'9' (positive integer)
- '*', '-', '+', '^' (operands)

operand order:
1) solve all powers (^) first
2) solve all products (*) next
3) then solve all sums (+)
4) finally solve all differences (-)

EXAMPLE:
s = "1+5*3^2-10+2"
1) 3^2 = 9
---> s = "1+5*9-10+2"
2) 5*9 = 45
---> s = "1+45-10+2"
3) 1+45 = 46 & 10+2 = 12
---> s = "46-12"
4) 46-12 = 34
---> result = "34"

HAVE FUN AND GOOD LUCK!

https://code.sololearn.com/c5FO89c3v1FA/?ref=app

Answer 1

https://code.sololearn.com/cDfv9X32nXE6/?ref=app

Answer 2

Here's my solution in Python.
My program solves any mathematical expression containing integers and the operators {+, -, *, /, ^}
It assumes operator precedence as follows:
1) ^
2) *, /
3) +, -
I used the normal mathematical operator precedence and didn't follow the unusual operator precedence of the challenge, but you can see in my code that it's trivial to change the precedence to be any other.

https://code.sololearn.com/cvBG8iHGc6Le

Answer 3

Here's my shot: https://code.sololearn.com/czA9J52R5omw/?ref=app
Please read the first comment in the code to run this effectively in SoloLearn. Running in command line is optimal and self-explanatory.

The only downfall here that I can think of is handling negative integers. For example, my code will spit out an error if you try to put in -6+7 or so but @Julian says that's invalid for this challenge anyway.

Answer 4

ADDITIONAL INFO:
- If any other character occurs in the string you can return -12345.
- If the string isn't mathematically valid:
s = "*2" OR s = "1*+2" OR s = "12-" ... (and so on)
All these aren't valid and you can return -12345.

AND DO NOT USE NORMAL OPERATOR PRECENDENCE!!!

Answer 5

https://code.sololearn.com/cotiQl6Zv6jB/?ref=app

Answer 6

@Sivan Tal

i don't want you to use normal operator precendence...

and i excluded '/' cause there are only positive INTEGERS allowed ;)

Answer 7

Does it count if we make it the short way?
Took me 3 minutes😂

https://code.sololearn.com/c9nlHDNot3C0/?ref=app

Answer 8

https://code.sololearn.com/WbgKNb9ZTFSE/?ref=app

Answer 9

I did it in Java. I welcome your suggestions and modifications.
https://code.sololearn.com/c37z7l7ed08L/?ref=app

Answer 10

NEW DAILY CHALLENGE FOR YOU:

https://www.sololearn.com/discuss/649970/?ref=app

Answer 11

@Julian you have an error in your example (assuming the regular operator precedence rules).
1+45-10+2 equals 38, not 34.

Answer 12

Well, I posted a solution that supports division. The input may contain only integers but the tesults may be a float.

Answer 13

@Tim Thuma
Your solution is short and elegant, but it doesn't catch invalid expressions, it doesn't let you choose the operators allowed, and it doesn't let you control their precedence. Therefore, it's not a good solution to the problem at hand.

Answer 14

@Sivan Tal I made this just for a little fun, not to give totally correct answer for challenge.

Answer 15

Tim, for the fun, try the following inputs to your program:
sum
i
i**2
:-)

Answer 16

@Sayantan - try the following inputs to your program:
sum
x
x**2

Answer 17

@ JULIAN
HERE IS MINE

1) give input with only integers/floats and operators

2) invalid input of any type will show why and how that is invalid

3) eg: 5/6*7/8.8^2.1-5+56
eg: 2.4/5.6^3*8.1
eg: 4-5-6-7+6+6*7*8*9

4) detailed step by step calculation is included.

check it out...

https://code.sololearn.com/cbEt2Rn86C5l/?ref=app

Answer 18

Short one, easy to maintain and to add new functions. https://code.sololearn.com/c7EdK2f9y1Fq/?ref=app

Answer 19

ANOTHER MINI-CHALLENGE HERE:
https://www.sololearn.com/discuss/650079/?ref=app

Answer 20

NEW *DAILY CHALLENGE* HERE:
https://www.sololearn.com/discuss/659673/?ref=app