Any combination where all consecutive numbers are present is unsolvable. That is [1..n], in any order.
That's because it is impossible to split any number, because it will create a duplicate, it is also impossible to merge, because it will either create a duplicate or a number >n
[2..n] (in any order) is also unsolvable for the same reason. And certainly many others ex:[1,2,4], finding if a problem is solvable is interesting in itself. A good solver should nor only find the shortest solution(s) if there is one but also determine if it is solvable. An interesting problem in itself.
That's because it is impossible to split any number, because it will create a duplicate, it is also impossible to merge, because it will either create a duplicate or a number >n
[2..n] (in any order) is also unsolvable for the same reason. And certainly many others ex:[1,2,4], finding if a problem is solvable is interesting in itself. A good solver should nor only find the shortest solution(s) if there is one but also determine if it is solvable. An interesting problem in itself.