2020/20v1

y2020/p20.py

+# flake8: noqa
+import re
+import collections
+import itertools
+import sys
+import math
+
+import toolkit
+
+
+def apply(cell):
+    key, *fns = cell
+    string = tiles[key]
+    for fn in fns:
+        if fn is not None:
+            string = fn(string)
+    return string
+
+
+def apply2(string, fns):
+    for fn in fns:
+        if fn is not None:
+            string = fn(string)
+    return string
+
+
+def render(grid):
+    return '\n'.join(
+        '\n'.join(''.join([n[1:-1]
+            for n in ln])
+        for ln in zip(*[apply(cell).splitlines()[1:-1] for cell in row]))
+        for row in grid
+    )
+
+
+def get_borders(content):
+    a, *_, b = content.splitlines()
+    c, *_, d = [''.join(ln) for ln in zip(*content.splitlines())]
+    return [a, b, c, d, a[::-1], b[::-1], c[::-1], d[::-1]]
+
+
+def flipV(string):
+    return '\n'.join(ln for ln in string.splitlines()[::-1])
+
+
+def flipH(string):
+    return '\n'.join(ln[::-1] for ln in string.splitlines())
+
+
+def rot90(n):
+    def inner(string):
+        return toolkit.render({k * 1j ** n: v for k, v in toolkit.read_image(string)[0].items()})
+    return inner
+
+
+text = sys.stdin.read().strip()
+tiles = {}
+borders = {}
+for line in text.split('\n\n'):
+    title, content = line.split(':\n')
+    tid = int(title.split()[1])
+    tiles[tid] = content
+    borders[tid] = get_borders(content)
+
+
+size = int(len(borders) ** 0.5)
+
+
+adj = collections.defaultdict(set)
+for (aid, A), (bid, B) in itertools.combinations(borders.items(), 2):
+    if set(A) & set(B):
+        adj[aid].add(bid)
+        adj[bid].add(aid)
+
+corn = [v for v, ks in adj.items() if len(ks) == 2]
+
+gids = [[None for _ in range(size)] for _ in range(size)]
+
+gids[0][0] = corn[0]
+gids[1][0], gids[0][1] = adj[gids[0][0]]
+gids[1][1], = adj[gids[1][0]] & adj[gids[0][1]] - {gids[0][0]}
+
+for x in range(2, size):
+    gids[0][x], = adj[gids[0][x - 1]] - {gids[0][x - 2], gids[1][x - 1]}
+    gids[1][x], = adj[gids[0][x]] & adj[gids[1][x - 1]] - {gids[0][x - 1]}
+
+for y in range(2, size):
+    gids[y][0], = adj[gids[y - 1][0]] - {gids[y - 2][0], gids[y - 1][1]}
+    for x in range(1, size):
+        gids[y][x], = adj[gids[y][x - 1]] & adj[gids[y - 1][x]] - {gids[y - 1][x - 1]}
+
+
+grid = [[(gids[y][x],) for x in range(size)] for y in range(size)]
+grid[0][0] += (flipV,)
+
+options = list(itertools.product([None, flipH], [None, flipV], [None] + [rot90(n) for n in range(3)]))
+
+for x in range(1, size):
+    goal = [ln[-1] for ln in apply(grid[0][x - 1]).splitlines()]
+    for chain in options:
+        if goal == [ln[0] for ln in apply(grid[0][x] + chain).splitlines()]:
+            grid[0][x] += chain
+            break
+
+for y in range(1, size):
+    for x in range(size):
+        goal = apply(grid[y - 1][x]).splitlines()[-1]
+        for chain in options:
+            if goal == apply(grid[y][x] + chain).splitlines()[0]:
+                grid[y][x] += chain
+                break
+
+
+monster = '''                  #
+#    ##    ##    ###
+ #  #  #  #  #  #   '''
+kuk, W, H = toolkit.read_image(monster)
+goal = re.compile(toolkit.render(kuk).replace('\n', '').replace(' ', '.'))
+
+cnt = 0
+for chain in options:
+    grody = apply2(render(grid), chain)
+    grok = [list(line) for line in grody.splitlines()]
+    for y in range(len(grok) - H):
+        for x in range(len(grok[0]) - W):
+            sample = ''.join(''.join(grok[y + dy][x + dx] for dx in range(W)) for dy in range(H))
+            cnt += bool(goal.fullmatch(sample))
+    if cnt:
+        break
+
+print(grody)
+print(grody.count('#') - cnt * monster.count('#'))