Discussion on: AoC Day 10: The Stars Align

from scipy.optimize import minimize
import numpy as np
from parse import parse


filename = 'input'
filepath = f'data/{filename}.plain'

positions = []
velocities = []

pattern = 'position=<{px},{py}> velocity=<{vx},{vy}>'

for line in open(filepath):
    result = parse(pattern, line)
    position = (int(result['px']), int(result['py']))
    positions.append(position)
    velocity = (int(result['vx']), int(result['vy']))
    velocities.append(velocity)

positions_nda = np.array(positions)
velocities_nda = np.array(velocities)


def gen_area(iterations, initial_positions, velocities):
    positions = initial_positions + velocities * i
    x_min, y_min = positions.min(axis=0)
    x_max, y_max = positions.max(axis=0)
    w = x_max - x_min
    h = y_max - y_min
    area = w * h
    return area


# identify the second that minimizes the dispersion of points
t = minimize(gen_area, 0, (positions_nda, velocities_nda))
second = int(np.round(t.x))

positions_nda += velocities_nda * second


def draw(positions_nda):

    x_min, y_min = positions_nda.min(axis=0)
    x_max, y_max = positions_nda.max(axis=0)

    for y in range(y_min, y_max + 1):
        line = ''
        for x in range(x_min, x_max + 1):
            if [x, y] in positions_nda.tolist():
                line += '#'
            else:
                line += '.'
        print(line)


draw(positions_nda)