1 files changed, 28 insertions, 0 deletions

diff --git a/2019/day6/orbits.py b/2019/day6/orbits.py
new file mode 100644
index 0000000..652256f
--- /dev/null
+++ b/2019/day6/orbits.py
@@ -0,0 +1,28 @@
+# this solves part 2
+import sys
+
+import networkx as nx
+
+
+def main(argv):
+
+    G = nx.DiGraph()
+    with open(argv[0]) as fp:
+        for line in fp:
+            line = line.rstrip("\n")
+            start, end = line.split(")")
+            G.add_node(start, label=start)
+            G.add_node(end, label=end)
+            G.add_edge(start, end)
+
+    jump_to = nx.lowest_common_ancestor(G, "SAN", "YOU")  # SAN and YOU are given
+    jumps = (
+        len(nx.shortest_path(G, jump_to, "SAN"))
+        + len(nx.shortest_path(G, jump_to, "YOU"))
+        - 4
+    )  # 4 because len includes start and end, so -2 times 2
+    print(jumps)
+
+
+if __name__ == "__main__":
+    main(sys.argv[1:])