Solve 2023:14 "Parabolic Reflector Dish"

2023-python/output/day_14.py

@@ -0,0 +1,83 @@
+from output import answer
+
+n = 14
+title = "Parabolic Reflector Dish"
+
+
+@answer(1, "Total initial load on the northern beams: {}")
+def part_1(presolved):
+    return presolved[0]
+
+
+@answer(2, "After some humble load testing, the northern beam load is {}")
+def part_2(presolved):
+    return presolved[1]
+
+
+BAEST = 1000_000_000
+
+
+def presolve(data):
+    m = [list(l) for l in data.split()]
+    s = len(m[0])
+    m1 = _tilt(m)
+
+    p1 = sum(sum((s - w) * o.count("O") for o in r) for w, r in enumerate(m1))
+
+    def impl(rc):
+        return "".join(["".join(r) for r in rc])
+
+    i = 0
+    seen = []
+    while True:
+        i += 1
+        for _ in range(4):
+            m = _tilt(m)
+            m = _rotate(m)
+        im = impl(m)
+        if im in seen:
+            break
+        else:
+            seen.append(im)
+    m2 = m
+    c = seen.index(im) + 1
+    for _ in range((BAEST - i) % (i - c)):
+        for j in range(4):
+            m2 = _tilt(m2)
+            m2 = _rotate(m2)
+    p2 = sum(sum((s - w) * o.count("O") for o in r) for w, r in enumerate(m2))
+    return p1, p2
+
+
+def _rotate(m):
+    return [list(l) for l in zip(*m[::-1])]
+
+
+def _tilt(m):
+    m = [list(l) for l in zip(*m)]
+    h = len(m[0])
+    for c in m:
+        u = True
+        while u:
+            u = False
+            for i in range(h - 1):
+                j = i + 1
+                if c[i] == "#" or c[j] == "#":
+                    continue
+                if c[i] < c[j]:
+                    c[j], c[i] = c[i], c[j]
+                    u = True
+    return [list(l) for l in zip(*m)]
+
+
+if __name__ == "__main__":
+    with open("./input/14.txt", "r") as f:
+        inp = f.read().strip()
+
+    inp = presolve(inp)
+
+    a = part_1(inp)
+    b = part_2(inp)
+
+    assert a == 109596
+    assert b == 96105