Advent of Code 2022 Day 15

import re

scan_row = 2000000
non_beacons = set()

discs = []

with open('input', 'r') as f:
    for line in f.readlines():
        sx, sy, bx, by = (int(z[1:]) for z in re.findall(r'=-?\d+', line))
        radius = abs(bx-sx) + abs(by-sy)
        discs.append((sx, sy, radius))

        dist_to_scan_row = abs(scan_row - sy)
        num_steps_left = radius - dist_to_scan_row

        if num_steps_left < 0:
            continue

        for x in range(sx - num_steps_left, sx + num_steps_left + 1):
            pos = (x, scan_row)
            if pos != (bx, by):
                non_beacons.add(pos)

print("part 1:", len(non_beacons))

def get_boundary(x, y, r):
    temp = (x, y+r)
    while temp != (x+r, y):
        temp = (temp[0]+1, temp[1]-1)
        yield temp
    while temp != (x, y-r):
        temp = (temp[0]-1, temp[1]-1)
        yield temp
    while temp != (x-r, y):
        temp = (temp[0]-1, temp[1]+1)
        yield temp
    while temp != (x, y+r):
        temp = (temp[0]+1, temp[1]+1)
        yield temp

# part 2
for x, y, r in discs:
    print("disc {} {} {}".format(x, y, r))
    for px, py in get_boundary(x, y, r+1):
        if 0 <= px <= 4000000 and 0 <= py <= 4000000:
            for dx, dy, dr in discs:
                if (abs(px-dx) + abs(py-dy)) <= dr:

                    break
            else:
                print("beacon:", px, py)
                print("tuning freq:", 4000000 * px + py)
                break