Poetry stuff.

src/holt59/aoc/2023/day9.py

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+import sys
+
+lines = sys.stdin.read().splitlines()
+
+data = [[int(c) for c in line.split()] for line in lines]
+
+right_values: list[int] = []
+left_values: list[int] = []
+for values in data:
+    diffs = [values]
+    while any(d != 0 for d in diffs[-1]):
+        diffs.append([rhs - lhs for lhs, rhs in zip(diffs[-1][:-1], diffs[-1][1:])])
+
+    rhs: list[int] = [0]
+    lhs: list[int] = [0]
+    for cx in range(len(diffs) - 1):
+        rhs.append(diffs[-cx - 2][-1] + rhs[cx])
+        lhs.append(diffs[-cx - 2][0] - lhs[cx])
+
+    right_values.append(rhs[-1])
+    left_values.append(lhs[-1])
+
+# part 1
+answer_1 = sum(right_values)
+print(f"answer 1 is {answer_1}")
+
+# part 2
+answer_2 = sum(left_values)
+print(f"answer 2 is {answer_2}")