Day 7

day07/part2.py

@@ -0,0 +1,38 @@
+from day07.common import BaseGraph
+
+
+class Graph(BaseGraph):
+
+    def depth_first_search(self, start: str, search_contained_by: bool = False):
+        visited = []
+
+        def count_bags(nxt):
+            if nxt not in self._nodes:
+                return 0
+            node = self._nodes[nxt]
+            if node.visited:
+                return node.count
+            node.visited = True
+            visited.append(node)
+            iter_over = node.contained_by if search_contained_by else node.contains
+            cnt = sum(val*count_bags(key) for key, val in iter_over.items()) + 1
+            node.count = cnt
+            return cnt
+
+        overall_cnt = count_bags(start)
+        for visit in visited:
+            visit.visited = False
+            visit.count = 0
+        return overall_cnt
+
+
+graph = Graph()
+lines = (x.strip() for x in open("input.txt"))
+count = -1
+
+for line in lines:
+    graph.add_line(line)
+
+count = graph.depth_first_search("shiny gold", search_contained_by=False) - 1
+
+print(count)