CODEWITHSUNDEEP
pythonpython-3.x
Yakob
Yakob

Reputation: 159

program to rotate list of numbers until all numbers have moved back to origioal position

I'm trying to write a program were given a list, the program reads through a list and rotates the numbers in the list one position for each interaction until the numbers reach starting position.

example of required output:

list : 1 2 3 4
[1,2,3,4]
[2,3,4,1]
[3,4,1,2]
[4,1,2,3]
[1,2,3,4]

I have written code to do this but it's not efficient and doesn't print how I would like it.

def rotation(n):
  rotations = set()
  for i in range( len( str(n) ) ):
    m = int( str(n)[i:] + str(n)[:i] )
    rotations.add(m)
  return rotations

print(rotation(1234))

the output for this code is

{1234, 4123, 3412, 2341}

if anyone could help me out with this, would be greatly appreciated.

Upvotes: 0

Views: 119

Answers (2)

Zero
Zero

Reputation: 1899

Do this,

def rotation(series):
  for i in range(len(series) + 1):
    print(series)
    series = series[1:] + series[:1]

rotation([1,2,3,4])

[1, 2, 3, 4]
[2, 3, 4, 1]
[3, 4, 1, 2]
[4, 1, 2, 3]
[1, 2, 3, 4]

Upvotes: 1

Samwise
Samwise

Reputation: 71424

It's not clear why you're operating on the number 1234 when you want to operate on the list [1, 2, 3, 4], or why your function is returning a set when you want the output to contain a repeated element. All this does is make the problem more complicated.

Just have the function take the original list and print each rotation:

>>> def rotation(nums):
...     for i in range(len(nums)+1):
...         print(nums[i:] + nums[:i])
...
>>> rotation([1, 2, 3, 4])
[1, 2, 3, 4]
[2, 3, 4, 1]
[3, 4, 1, 2]
[4, 1, 2, 3]
[1, 2, 3, 4]

Upvotes: 2

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