Advent of Code 2024 Day 14

— Day 14: Restroom Redoubt —

Watch out for the robot guards!

Predict the motion of the robots in your list within a space which is 101 tiles wide and 103 tiles tall. What will the safety factor be after exactly 100 seconds have elapsed?

import re

with open('data-2024-14.txt', 'r') as f:
    inp = f.read().splitlines()

robots = []

for i in inp: 
    rb = {}
    rb['px'] = int(re.findall(r'p=(\d+)', i)[0])
    rb['py'] = int(re.findall(r'p=\d+,(\d+)', i)[0])
    rb['vx'] = int(re.findall(r'v=(-*\d+)', i)[0])
    rb['vy'] = int(re.findall(r'v=-*\d+,(-*\d+)', i)[0])
    robots.append(rb)
    
# robots

Prep done, make a function.

# wide = 101
# tall = 103
# 100 seconds

finals = []

def move_robots(rob): 
    # total distance moved after 100 seconds
    dist_x = rob['vx'] * 100
    dist_y = rob['vy'] * 100
    # remainder of movement since we loop around
    move_x = dist_x % 101
    move_y = dist_y % 103
    # relative position
    p1x = rob['px'] + move_x
    p1y = rob['py'] + move_y
    # final position because we need to adjust
    if p1x < 0: 
        fx = 101 + p1x
    elif p1x > 100:
        fx = p1x - 101
    else: 
        fx = p1x
    if p1y < 0: 
        fy = 103 + p1y
    elif p1y > 102:
        fy = p1y - 103
    else: 
        fy = p1y
    # return
    return [fx, fy]
        
        
for r in robots: 
    pos = move_robots(r)
    finals.append(pos)
    
nw = 0
ne = 0
sw = 0
se = 0

for f in finals: 
    if f[0] < 50 and f[1] < 51: 
        nw += 1
    elif f[0] < 50 and f[1] > 51: 
        sw += 1
    elif f[0] > 50 and f[1] < 51: 
        ne += 1
    elif f[0] > 50 and f[1] > 51: 
        se += 1
        
nw, ne, sw, se
nw * ne * sw * se

# 230461440

230461440

— Part Two —

Hey! The robots make a christmas tree picture at some stage.

What is the fewest number of seconds that must elapse for the robots to display the Easter egg?

from PIL import Image
from copy import deepcopy
import numpy as np
import csv

bots = deepcopy(robots)

# image = Image.fromarray(numpy_array)
# image.save('file name with extension(like .jpg)')
  
def move_bots(rob): 
    # move the robots
    p1x = rob['px'] + rob['vx']
    p1y = rob['py'] + rob['vy']
    # final position because we need to adjust
    if p1x < 0: 
        fx = 101 + p1x
    elif p1x > 100:
        fx = p1x - 101
    else: 
        fx = p1x
    if p1y < 0: 
        fy = 103 + p1y
    elif p1y > 102:
        fy = p1y - 103
    else: 
        fy = p1y
    # return
    return fx, fy


for x in range(100): 
    pic = np.zeros([101,103])
    # do one iteration for moving
    for r in robots: 
        r['px'], r['py'] = move_bots(r)
        pic[r['px'], r['py']] = 8
    # export the array
    # export=open(f'day14/pic{x}.jpg', 'wb')
    np.savetxt(f'out-day14/pic{x}.txt', pic, delimiter='', fmt='%0.f')