Solve 2023:09 "Mirage Maintenance"

2023-python/output/day_09.py

@@ -0,0 +1,39 @@
+from output import answer, puzzleinput
+
+n = 9
+title = "Mirage Maintenance"
+
+
+@answer(1, "OASIS report extrapolated values sum is {}")
+def part_1(data):
+    lines = [[int(d) for d in line.split()] for line in data.splitlines()]
+    return _solve(lines)
+
+
+@answer(2, "Using prepending, OASIS report extrapolated values sum is {}")
+def part_2(data):
+    lines = [[int(d) for d in line.split()[::-1]] for line in data.splitlines()]
+    return _solve(lines)
+
+
+def _solve(lines):
+    vs = 0
+    for l in lines:
+        h = [l]
+        while any(n != 0 for n in h[-1]):
+            h.append([b - a for a, b in zip(h[-1], h[-1][1:])])
+        h = h[::-1]
+        for i in range(len(h)):
+            h[i].append(0 if i == 0 else h[i - 1][-1] + h[i][-1])
+        vs += h[-1][-1]
+    return vs
+
+
+if __name__ == "__main__":
+    inp = parse_input()
+
+    a = part_1(inp)
+    b = part_2(inp)
+
+    assert a == 1702218515
+    assert b == 925