Day 23: Crab Cups

Classes:

Cup(label[, next_cup])	Represent a cup with a label and the cup next to it clockwise.
CupCircle()	Represent a circle of cups as a circular linked list.

Functions:

cup_circle_to_str(cup_circle)	Stringify the labels of the cup_circle, starting from the current cup.
initialize_cups(cup_labels)	Create a CupCircle from cup_labels.
crab_move(cup_circle)	Perform one move by the crab.
solve_100_steps(cup_labels)	Solve the problem for 100 crab moves.

class Cup(label: int, next_cup: Optional[Cup] = None)

Represent a cup with a label and the cup next to it clockwise.

Methods:

__init__(label[, next_cup])

Initialize with the given values.

Attributes:

label	label of the cup
next_cup	the next cup clockwise

__init__(label: int, next_cup: Optional[Cup] = None) → None

Initialize with the given values.

label: int

label of the cup

next_cup: Cup

the next cup clockwise

class CupCircle

Represent a circle of cups as a circular linked list.

Methods:

__init__()	Initialize the circle as an empty circular linked list.
add_new_cup(label)	Add a new cup to the circle with label.
__repr__()	Represent the circle as its labels.
__eq__(other)	Return whether two circles are identical in the labels of the circle.
__len__()	Return the number of cups in the circle.

Attributes:

current_cup

the cup from which each new move starts

__init__() → None

Initialize the circle as an empty circular linked list.

current_cup: Optional[Cup]

the cup from which each new move starts

add_new_cup(label: int) → None

Add a new cup to the circle with label.

The cup is added next to the current cup counter-clockwise.

Requires

• label >= 0

• not self._is_label_in_circle(label)

__repr__() → str

Represent the circle as its labels.

__eq__(other: object) → bool

Return whether two circles are identical in the labels of the circle.

__len__() → int

Return the number of cups in the circle.

cup_circle_to_str(cup_circle: CupCircle) → str

Stringify the labels of the cup_circle, starting from the current cup.

Ensures

• cup_circle == initialize_cups(result)

initialize_cups(cup_labels: str) → CupCircle

Create a CupCircle from cup_labels.

Requires

• len(set(cup_labels)) == len(cup_labels)

• NUMBER_RE.fullmatch(cup_labels)

Ensures

• cup_labels == cup_circle_to_str(result)

crab_move(cup_circle: CupCircle) → None

Perform one move by the crab.

Requires

• len(cup_circle) >= 5

OLD

• .len_cup_circle = len(cup_circle)

Ensures

• OLD.len_cup_circle == len(cup_circle)

solve_100_steps(cup_labels: str) → CupCircle

Solve the problem for 100 crab moves.

Requires

• len(set(cup_labels)) == len(cup_labels)

• NUMBER_RE.fullmatch(cup_labels)

• len(cup_labels) >= 5

Ensures

• len(cup_labels) == len(result)