Finally solve 2019 day 12 and others

2020/d10.py

@@ -0,0 +1,57 @@
+from lib import get_data
+from collections import defaultdict
+from functools import lru_cache
+
+
+@lru_cache
+def count(xs, current, target):
+    delta_target = target - current
+    if len(xs) == 0:
+        if delta_target <= 3:
+            return 1
+        else:
+            return 0
+
+    x = xs[0]
+    xs = xs[1:]
+
+    total = 0
+    delta = x - current
+
+    if delta > 3:
+        return 0
+
+    if delta <= 3:
+        total += count(xs, x, target)
+
+    total += count(xs, current, target)
+    return total
+
+
+def part_1(data):
+    xs = list(map(int, data.strip().splitlines()))
+    out = max(xs) + 3
+    ds = defaultdict(int)
+
+    c = 0
+    for x in sorted(xs):
+        d = x - c
+        ds[d] += 1
+        c = x
+    d = out - c
+    ds[d] += 1
+
+    a, b = list(ds.values())
+    print(a * b)
+
+    xs = tuple(sorted(xs))
+    print(count(xs, 0, out))
+
+
+def main():
+    data = get_data(__file__)
+    part_1(data)
+
+
+if __name__ == "__main__":
+    main()

2020/d11.py

@@ -0,0 +1,89 @@
+from lib import get_data, Grid2D, add2
+
+data = """L.LL.LL.LL
+LLLLLLL.LL
+L.L.L..L..
+LLLL.LL.LL
+L.LL.LL.LL
+L.LLLLL.LL
+..L.L.....
+LLLLLLLLLL
+L.LLLLLL.L
+L.LLLLL.LL"""
+
+
+def part_1(data):
+    g = Grid2D(data)
+    seen = set()
+    while True:
+        h = g.hash()
+        if h in seen:
+            break
+        seen.add(h)
+
+        ng = g.clone_with_val(".")
+        for r in range(g.n_rows):
+            for c in range(g.n_cols):
+                p = (r, c)
+                s = g[p]
+                if s == ".":
+                    continue
+                occupied = sum([1 if g[nb] == "#" else 0 for nb in g.neighbors_adj(p)])
+                if s == "L" and occupied == 0:
+                    ng[p] = "#"
+                elif s == "#" and occupied >= 4:
+                    ng[p] = "L"
+                else:
+                    ng[p] = s
+        g = ng
+    print(len(g.find("#")))
+
+
+def part_2(data):
+    g = Grid2D(data)
+    seen = set()
+    while True:
+        h = g.hash()
+        if h in seen:
+            break
+        seen.add(h)
+
+        ng = g.clone_with_val(".")
+        for r in range(g.n_rows):
+            for c in range(g.n_cols):
+                p = (r, c)
+                s = g[p]
+                if s == ".":
+                    continue
+
+                occupied = 0
+                for dir in g.COORDS_ORTH + g.COORDS_DIAG:
+                    np = p
+                    while True:
+                        np = add2(np, dir)
+                        if not g.contains(np):
+                            break
+                        elif g[np] == "#":
+                            occupied += 1
+                            break
+                        elif g[np] == "L":
+                            break
+
+                if s == "L" and occupied == 0:
+                    ng[p] = "#"
+                elif s == "#" and occupied >= 5:
+                    ng[p] = "L"
+                else:
+                    ng[p] = s
+        g = ng
+    print(len(g.find("#")))
+
+
+def main():
+    data = get_data(__file__)
+    part_1(data)
+    part_2(data)
+
+
+if __name__ == "__main__":
+    main()