2023/day11.py

import fileinput
import math
from pprint import pprint
from itertools import pairwise


def main():
    (part1, part2) = (0, 0)

    # parse
    inp = fileinput.input()
    coords_ = []
    (w, h) = (0, 0)
    for (y, row) in enumerate(inp):
        for (x, c) in enumerate(row):
            if c == "#":
                coords_.append((x, y))
                w = max(w, x)
                h = max(h, y)

    coords = coords_.copy()

    (dx, dy) = (0, 0)
    for j in range(h):
        if not any(y_ == j + dy for (_, y_) in coords):
            print(f"inserting row at y={j}")
            for i in range(len(coords)):
                (x_, y_) = coords[i]
                if y_ > j + dy:
                    coords[i] = (x_, y_ + 1)
            dy += 1
        if not any(x_ == j + dx for (x_, _) in coords):
            print(f"inserting column at x={j}")
            for i in range(len(coords)):
                (x_, y_) = coords[i]
                if x_ > j + dx:
                    coords[i] = (x_ + 1, y_)
            dx += 1

    part1 = 0
    for ai in range(len(coords)):
        for bi in range(ai + 1, len(coords)):
            (ax, ay) = coords[ai]
            (bx, by) = coords[bi]
            part1 += abs(ax - bx) + abs(ay - by)

    coords = coords_.copy()
    L = 1_000_000 - 1

    (dx, dy) = (0, 0)
    for j in range(h):
        if not any(y_ == j + dy for (_, y_) in coords):
            print(f"inserting rows at y={j}")
            for i in range(len(coords)):
                (x_, y_) = coords[i]
                if y_ > j + dy:
                    coords[i] = (x_, y_ + L)
            dy += L
        if not any(x_ == j + dx for (x_, _) in coords):
            print(f"inserting columns at x={j}")
            for i in range(len(coords)):
                (x_, y_) = coords[i]
                if x_ > j + dx:
                    coords[i] = (x_ + L, y_)
            dx += L

    part2 = 0
    for ai in range(len(coords)):
        for bi in range(ai + 1, len(coords)):
            (ax, ay) = coords[ai]
            (bx, by) = coords[bi]
            part2 += abs(ax - bx) + abs(ay - by)

    print(part1, part2)


if __name__ == "__main__":
    main()