Solve 2023:13 "Point of Incidence"

2023-python/output/day_13.py

@@ -0,0 +1,56 @@
+from output import answer
+
+n = 13
+title = "Point of Incidence"
+
+
+@answer(1, "Summarizing the notes gives {}")
+def part_1(presolved):
+    return presolved[0]
+
+
+@answer(2, "Summarizing the notes allowing off-by-1 gives {}")
+def part_2(presolved):
+    return presolved[1]
+
+
+def presolve(data):
+    g = [l.split() for l in data.split("\n\n")]
+
+    p1 = sum(d * n for d, n in _inspect(g))
+    p2 = sum(d * n for d, n in _inspect(g, 1))
+
+    return p1, p2
+
+
+def _inspect(g, a=0):
+    af = []
+    for m in g:
+        for d, n in [(100, m), (1, tuple(zip(*m)))]:
+            af.append((d, _compare(n, a)))
+    return af
+
+
+def _compare(l, a=0):
+    for i in range(1, len(l)):
+        if (
+            sum(
+                sum(a != b for a, b in zip(x, y)) for x, y in zip(l[i - 1 :: -1], l[i:])
+            )
+            == a
+        ):
+            return i
+    return 0
+
+
+if __name__ == "__main__":
+    with open("./input/13.txt", "r") as f:
+        inp = f.read().strip()
+
+    inp = presolve(inp)
+
+    a = part_1(inp)
+    b = part_2(inp)
+
+    assert a == 29213
+    assert b == 37453