This was a quick hobby project made to answer a question a friend of mine asked in December 2022:
Using 4 different numbers from the set {2, 3, 4, 5, 7, 8, 9, 44, 55}, in how many different ways can these numbers be combined using the arithmetic operators
+,-,/, and*, to get a result of 14?
Up to the answerer whether using parentheses is allowed or not.
Note:2 + 3 + 4 + 5,(2 + 3) + 4 + 5, and3 + 2 + 4 + 5do not count as different from each other.
At first, I thought this would take a few hours to solve,
but I ended up spending about three days during Christmas working almost non-stop to solve this.
My initial underestimation of this task also caused me to put off writing unit tests for longer than I should have,
which caused quite a lot of pain over repeatedly breaking previously-working functionality.
This was a fascinating and fun little problem to work on, and I am fairly confident I arrived at a correct solution by the end.
The program doesn't take arguments, so you'll need to modify the source code if you want to change options such as:
- the initial set of numbers
- the target number
- whether parentheses are allowed or not
- whether a number can be used multiple times