Day 9 Completed

put example_input.txt back in repos, for unittest purposes

day9/part2.py

@@ -0,0 +1,7 @@
+#!/usr/bin/env python3.11
+from common import OASISLine
+
+if __name__ == "__main__":
+    analysis = OASISLine.parse("input.txt")
+    extrapolation = map(lambda o: o.reduce().extrapolate_back(), analysis)
+    print(sum(extrapolation))