2021/day20.py

@@ -1,38 +0,0 @@
-from operator import itemgetter as ig
-
-with open("input20.txt") as f:
-    lines = [line.rstrip() for line in f]
-iea = lines[0]
-data = {
-    (x, y): c == "#"
-    for x, line in enumerate(lines[2:])
-    for y, c in enumerate(line)
-}
-
-
-def near(x, y):
-    return ((a, b) for a in range(x - 1, x + 2) for b in range(y - 1, y + 2))
-
-
-def enhance(image, unkv):
-    next_image = {}
-    xmin, ymin = min(image, key=ig(0))[0] - 1, min(image, key=ig(1))[1] - 1
-    xmax, ymax = max(image, key=ig(0))[0] + 1, max(image, key=ig(1))[1] + 1
-    for x in range(xmin, xmax + 1):
-        for y in range(ymin, ymax + 1):
-            v = 0
-            for nnp in near(x, y):
-                v = (v << 1) | int(image.get(nnp, unkv))
-            next_image[(x, y)] = iea[v] == "#"
-    return next_image
-
-
-def solve(num_steps):
-    image = data
-    for i in range(num_steps):
-        image = enhance(image, i % 2 == 1)
-    print(sum(image.values()))
-
-
-solve(2)
-solve(50)

2021/day21.py

@@ -1,48 +0,0 @@
-from functools import cache
-
-with open("input21.txt") as f:
-    lines = [line.rstrip() for line in f]
-ipos = (int(lines[0].rsplit()[-1]), int(lines[1].rsplit()[-1]))
-
-pos = list(ipos)
-scores = [0, 0]
-num_rolls = 0
-turn = 0
-while scores[0] < 1000 and scores[1] < 1000:
-    roll = sum(range(num_rolls + 1, num_rolls + 4))
-    num_rolls += 3
-    pos[turn] = pos[turn] + roll
-    pos[turn] = pos[turn] - ((pos[turn] - 1) // 10) * 10
-    scores[turn] += pos[turn]
-    turn = (turn + 1) % 2
-print(min(scores) * num_rolls)
-
-rolls_prob = [
-    a + b + c for a in range(1, 4) for b in range(1, 4) for c in range(1, 4)
-]
-
-
-@cache
-def play(pos, scores, turn):
-    if scores[0] >= 21:
-        return 1, 0
-    if scores[1] >= 21:
-        return 0, 1
-
-    w1, w2 = 0, 0
-    nturn = (turn + 1) % 2
-    for r in rolls_prob:
-        p = pos[turn] + r
-        p = p - ((p - 1) // 10) * 10
-        if turn == 0:
-            npos = p, pos[1]
-            nscores = scores[0] + p, scores[1]
-        else:
-            npos = pos[0], p
-            nscores = scores[0], scores[1] + p
-        res1, res2 = play(npos, nscores, nturn)
-        w1, w2 = w1 + res1, w2 + res2
-    return w1, w2
-
-
-print(max(play(ipos, (0, 0), 0)))