Question

I have an matrix (array of arrays) in the form

[1, 2, 3, 4]
[12, 23, 34]
[123, 234]
[1234]

And want to produce sequences of this matrix that is following each other and is (converted to a string) in the same length as the array at index 0 (top-most). So i.e. the result of this would be

[1, 2, 3, 4]
[12, 3, 4]
[1, 23, 4]
[1, 2, 34]
[12, 34]
[123, 4]
[1, 234]
[1234]

The thing I want to achive is to get all parts of a string that can be directly connected to each other and splitted i sub arrays (as shown in the example).

The implementation language is irrelevant but preferably in i.e. Python, java, ruby, C#, clojure, Psudo code, or other language at a fairly high level.

Answer 1

I improved the code from my previous one.

a = ["1", "2", "3", "4"]

['', '.'].repeated_permutation(a.length - 1).map{|b| a.zip(b).join.split('.')}

will give you:

[
  ["1234"],
  ["123", "4"],
  ["12", "34"],
  ["12", "3", "4"],
  ["1", "234"],
  ["1", "23", "4"],
  ["1", "2", "34"],
  ["1", "2", "3", "4"]
]