2021/06.py
def calculate_lanternfish(start_seq: List[int], iterations: int) -> int:
    """
    This calculate function aggregates all of the lanternfish at the same stage in life
    together to keep track of them.

    Each day, all lanternfish at ``0`` days before they create a new lanternfish become
    a ``6`` and starts a new lanternfish initialized at ``8`` to the end of the list,
    while each other number decreases by ``1`` if it was present at the start of the
    day.
    """
    number_of_laternfish = defaultdict(int)
    for x in start_seq:
        number_of_laternfish[x] += 1

    for _ in range(iterations):
        new_number_of_lanternfish = defaultdict(int)
        for k, v in number_of_laternfish.items():
            if k == 0:
                # v lanternfishes is at 0, make `v` new lanternfishes, and reset all of
                # the lanternfish at 0 to 6.
                new_number_of_lanternfish[8] += v
                new_number_of_lanternfish[6] += v
            else:
                new_number_of_lanternfish[k - 1] += v
        number_of_laternfish = new_number_of_lanternfish

    return sum(number_of_laternfish.values())

    This calculate function aggregates all of the lanternfish at the same stage in life
    together to keep track of them.

    Each day, all lanternfish at ``0`` days before they create a new lanternfish become
    a ``6`` and starts a new lanternfish initialized at ``8`` to the end of the list,
    while each other number decreases by ``1`` if it was present at the start of the
    day.
    
This calculate function aggregates all of the lanternfish at the same stage in life
together to keep track of them.


This calculate function aggregates all of the lanternfish at the same stage in life together to keep track of them .
def calculate_lanternfish(start_seq: List[int], iterations: int) -> int:
    number_of_laternfish = defaultdict(int)
    for x in start_seq:
        number_of_laternfish[x] += 1
    for _ in range(iterations):
        new_number_of_lanternfish = defaultdict(int)
        for k, v in number_of_laternfish.items():
            if k == 0:
                new_number_of_lanternfish[8] += v
                new_number_of_lanternfish[6] += v
            else:
                new_number_of_lanternfish[k - 1] += v
        number_of_laternfish = new_number_of_lanternfish
    return sum(number_of_laternfish.values())
def calculate_lanternfish ( start_seq : List [ int ] , iterations : int ) -> int : number_of_laternfish = defaultdict ( int ) for x in start_seq : number_of_laternfish [ x ] += 1 for _ in range ( iterations ) : new_number_of_lanternfish = defaultdict ( int ) for k , v in number_of_laternfish . items ( ) : if k == 0 : new_number_of_lanternfish [ 8 ] += v new_number_of_lanternfish [ 6 ] += v else : new_number_of_lanternfish [ k - 1 ] += v number_of_laternfish = new_number_of_lanternfish return sum ( number_of_laternfish . values ( ) )
This calculate function aggregates all of the lanternfish at the same stage in life
together to keep track of them.
This calculate function aggregates all of the lanternfish at the same stage in life together to keep track of them .
"""
    This calculate function aggregates all of the lanternfish at the same stage in life
    together to keep track of them.

    Each day, all lanternfish at ``0`` days before they create a new lanternfish become
    a ``6`` and starts a new lanternfish initialized at ``8`` to the end of the list,
    while each other number decreases by ``1`` if it was present at the start of the
    day.
    """ # v lanternfishes is at 0, make `v` new lanternfishes, and reset all of # the lanternfish at 0 to 6.
start_seq
List[int]
iterations
int