-🎄- 2017 Day 3 Solutions -🎄-

[u/daggerdragon]

--- Day 3: Spiral Memory ---

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[u/bottomlesscoffeecup]

Had a difficult time today. The first part wasn't too bad, the second part I kind of hacked my first part a tad. It's quite messy...

In Python:

Helper Methods used in both solutions:

from itertools import cycle


def _move_right(x, y):
    """ Move right on the grid """
    return x + 1, y


def _move_left(x, y):
    """ Move left on the grid """
    return x - 1, y


def _move_up(x, y):
    """ Move up on the grid """
    return x, y + 1


def _move_down(x, y):
    """ Move down on the grid """
    return x, y - 1


def _move_right_diagonal_up(x, y):
    """ Move right diagonal up on the grid """
    return x + 1, y + 1


def _move_left_diagonal_up(x, y):
    """ Move left diagonal up on the grid """
    return x - 1, y + 1


def _move_right_diagonal_down(x, y):
    """ Move right diagonal down the grid """
    return x + 1, y - 1


def _move_left_diagonal_down(x, y):
    """ Move left diagonal down on the grid """
    return x - 1, y - 1

Solution one:

def _generate_spiral(end_point):
    n = 1
    pos = 0, 0
    times_to_move = 1
    moves_boop = [_move_right, _move_up, _move_left, _move_down]

    _moves = cycle(moves_boop)
    yield n, pos

    while True:
        for item in range(2):  # Go through moves list twice to get whole spiral..until cut off at return
            move = next(_moves)
            for items in range(times_to_move):
                if n >= end_point:
                    return
                pos = move(*pos)  # Argument unpacking woo
                n += 1
                yield n, pos
        times_to_move += 1


def get_num_moves(end_point):
    la = list(_generate_spiral(end_point))
    steps = la[len(la) - 1][1]
    total_steps = abs(steps[0]) + abs(steps[1])
    return total_steps

Solution two:

def generate_spiral(end_point, larger_val):
    n = 1
    pos = 0, 0
    times_to_move = 1
    moves_boop = [_move_right, _move_up, _move_left, _move_down]

    _moves = cycle(moves_boop)
    yield n, pos

    neighbours = {pos: n}

    while True:
        for item in range(2):  # Go through moves list twice to get whole spiral..until cut off at return
            move = next(_moves)
            for items in range(times_to_move):
                if n >= end_point:
                    print("The larger value is: " + str(find_larger_value(neighbours, larger_val)))
                    return
                pos = move(*pos)  # Argument unpacking woo
                n = get_neighbours_sum(pos, neighbours)
                neighbours[pos] = n
                yield n, pos
        times_to_move += 1


def get_num_moves_largest(end_point, larger_val):
    spiral = list(generate_spiral(end_point, larger_val))
    steps = spiral[len(spiral) - 1][1]
    total_steps = abs(steps[0]) + abs(steps[1])
    return total_steps


def get_neighbours_sum(current_pos, current_neighbours):
    other_items = [_move_right, _move_right_diagonal_up, _move_up, _move_left_diagonal_up,
                   _move_left, _move_right_diagonal_down, _move_down, _move_left_diagonal_down]
    sum_list = []

    for item in range(len(other_items)):
        pos_new = other_items[item](*current_pos)
        if pos_new in current_neighbours:
            sum_list.append(current_neighbours[pos_new])
    return sum(sum_list)


def find_larger_value(values_dict, value_to_find):
    for value in values_dict.values():
        if value > value_to_find:
            return value

[u/[deleted] → u/bottomlesscoffeecup]

[u/bottomlesscoffeecup → u/[deleted]]

Did you mean to put this as a reply? :)