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https://github.com/ashawley/abcdefghppp-scala
(AB − CD = EF) + GH = PPP
https://github.com/ashawley/abcdefghppp-scala
Last synced: 5 days ago
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(AB − CD = EF) + GH = PPP
- Host: GitHub
- URL: https://github.com/ashawley/abcdefghppp-scala
- Owner: ashawley
- License: gpl-3.0
- Created: 2018-11-02T10:03:22.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2019-12-17T05:57:24.000Z (about 5 years ago)
- Last Synced: 2024-10-31T12:46:51.418Z (about 2 months ago)
- Language: Scala
- Homepage: https://ashawley.github.io/ABCDEFGHPPP-scala/2.13.0-M5/api/
- Size: 980 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
ABCDEFGHPPP problem in Scala
============================
[](https://ci.appveyor.com/project/ashawley/ABCDEFGHPPP-scala)
[](https://circleci.com/gh/ashawley/ABCDEFGHPPP-scala)
[](https://travis-ci.org/ashawley/ABCDEFGHPPP-scala)
Problem: (_AB_ − _CD_ = _EF_) + _GH_ = _PPP_
AB
- CD
-----
EF
+ GH
-----
PPP
The values for _A_, _B_, _C_, _D_, _E_, _F_, _G_, _H_, and _P_
are distinct and in the range of [0, 9]. The values for _A_, _C_,
_E_, _G_ cannot be 0. The numbers cannot repeat.
**Hint**: There is no way for _PPP_ to be 000. There is no way for
_PPP_ to be 222 or greater. It can only be 111.
Solving the problem for a radix of 10:
```scala
ABCDEFGHPPP.solve(10) // Decimal
```
It's possible to solve for other base number systems than just
decimal.
```scala
ABCDEFGHPPP.solve(16) // Hex system
```
### Overview
This solution is written in [Scala] 2.12 and only depends on the Scala
standard library, and [Java 8].
The primary routine is called `solve`. It can give the set of all
solutions for the problem in decimal:
```scala
ABCDEFGHPPP.solve(10).foreach(println)
(9,0,2,7,6,3,4,8,1)
(9,0,6,3,2,7,8,4,1)
(8,5,4,6,3,9,7,2,1)
(8,6,5,4,3,2,7,9,1)
(9,5,2,7,6,8,4,3,1)
```
Alternatively, an application entry point, `main`, is provided:
```scala
ABCDEFGHPPP.main(Array())
```
Gives a listing of all the solutions:
```
Solution:
85
- 46
-----
39
+ 72
-----
111
Solution:
86
- 54
-----
32
+ 79
-----
111
Solution:
90
- 27
-----
63
+ 48
-----
111
Solution:
90
- 63
-----
27
+ 84
-----
111
Solution:
95
- 27
-----
68
+ 43
-----
111
Found 5 solutions
```
### Getting started
Use [sbt](http://www.scala-sbt.org/) to interact with the build.
```
$ sbt
```
You can run Scala from the sbt console:
```
sbt> console
scala> ABCDEFGHPPP.main(Array("16"))
```
```
Solution:
6 0
- 2 4
-------
3 c
+ d 5
-------
1 1 1
Solution:
6 0
- 3 4
-------
2 c
+ e 5
-------
1 1 1
...
```
Alternatively, you can interact with program as if it was built as a
command-line application but from sbt:
```
sbt> run 10
[info] Running ABCDEFGHPPP 10
Solution:
9 0
- 2 7
-------
6 3
+ 4 8
-------
1 1 1
...
Found 5 solutions
[success] Total time: 9 s, completed Nov 2, 2018 8:24:19 PM
```
### Caveats
Passing the empty string as an argument:
```
scala> ABCDEFGHPPP.main(Array(""))
java.lang.NumberFormatException: For input string: ""
```
Passing an argument that is something other than an Integer:
```
scala> ABCDEFGHPPP.main(Array("f"))
java.lang.NumberFormatException: For input string: "f"
```
Passing an argument that isn't a valid Integer:
```
scala> Int.MaxValue
res1: Int = 2147483647
scala> ABCDEFGHPPP.main(Array("2147483648"))
java.lang.NumberFormatException: For input string: ""
```
### References
- https://github.com/mingchuno/ABCDEFGHPPP
[Java 8]: http://docs.oracle.com/javase/8/docs/api/
[sbt]: http://scala-sbt.org
[Scala]: http://scala-lang.org