MHB Is the list a circular shift of the other?

[mathmari]

Hey!

I want to write a progarmm in python that reads two lists A, B and checks if the one of the lists is a circular shift of the other list. The result is either True or False.

I thought to do something like that:

if sorted(A) == sorted(B):
  C = True
else:
  C = False

But it cannot be correct because if we consider the lists A=[1, 2, 3, 4, 5] and B=[2, 3, 4, 1, 5], the sorted lists are the same, but B is not a circular shift of A. Right? (Wondering)

Could you give me a hint? (Wondering)

 

[I like Serena]

Hey!

I want to write a progarmm in python that reads two lists A, B and checks if the one of the lists is a circular shift of the other list. The result is either True or False.

I thought to do something like that:

if sorted(A) == sorted(B):
  C = True
else:
  C = False

But it cannot be correct because if we consider the lists A=[1, 2, 3, 4, 5] and B=[2, 3, 4, 1, 5], the sorted lists are the same, but B is not a circular shift of A. Right? (Wondering)

Could you give me a hint? (Wondering)

Hey mathmari! (Smile)

How about shifting list A cyclically, and comparing it to B?
And repeat until we've done all possible cyclical shifts of list A? (Wondering)

 

[MarkFL]

I would probably go about it in a bit clunkier fashion.

I would first determine if both lists had the same number of elements. If not, then the test fails.

If no fail, then I would see if the first element in list A is in list B...if not, then the test fails.

If no fail, then I would cycle through the two lists using modular arithmetic to determine the correct subscripts for the second list, and if all elements match, then success. :)