day 24 hurts my brain, thanks reddit

2024/day23/day23.py

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+from collections import defaultdict
+
+
+def part1(input: str) -> int:
+    graph: dict[str, set[str]] = defaultdict(set)
+    for line in input.splitlines():
+        parts = line.split("-")
+        graph[parts[0]].add(parts[1])
+        graph[parts[1]].add(parts[0])
+
+    ans_groups: set[str] = set()
+    for node in graph:
+        if node[0] != "t":
+            continue
+        neighbors = graph[node]
+        for neighbor in neighbors:
+            for neighbor2 in neighbors:
+                if neighbor == neighbor2:
+                    continue
+                if neighbor2 in graph[neighbor]:
+                    group: list[str] = [node, neighbor, neighbor2]
+                    group.sort()
+
+                    ans_groups.add(",".join(group))
+
+    return len(ans_groups)
+
+
+def part2(input: str) -> str:
+    graph: dict[str, set[str]] = defaultdict(set)
+    for line in input.splitlines():
+        parts = line.split("-")
+        graph[parts[0]].add(parts[1])
+        graph[parts[1]].add(parts[0])
+
+    seen: set[str] = set()
+    largest_group: set[str] = set()
+    for node in graph:
+        if node in seen:
+            continue
+        seen.add(node)
+
+        group: set[str] = {node}
+        for neighbor in graph[node]:
+            if check_group_against_new_node(group, graph, neighbor):
+                group.add(neighbor)
+                seen.add(neighbor)
+
+        if len(group) > len(largest_group):
+            largest_group = group
+
+    final_group: list[str] = list(largest_group)
+    final_group.sort()
+    return ",".join(final_group)
+
+
+def check_group_against_new_node(
+    group: set[str], graph: dict[str, set[str]], node_to_add: str
+) -> bool:
+    for node in group:
+        if node not in graph[node_to_add]:
+            return False
+
+    return True
+
+
+example = """kh-tc
+qp-kh
+de-cg
+ka-co
+yn-aq
+qp-ub
+cg-tb
+vc-aq
+tb-ka
+wh-tc
+yn-cg
+kh-ub
+ta-co
+de-co
+tc-td
+tb-wq
+wh-td
+ta-ka
+td-qp
+aq-cg
+wq-ub
+ub-vc
+de-ta
+wq-aq
+wq-vc
+wh-yn
+ka-de
+kh-ta
+co-tc
+wh-qp
+tb-vc
+td-yn"""
+
+input = open("input.txt").read().strip()
+
+print(f"part1 example: {part1(example)} want 7")
+print(f"part1 actual: {part1(input)} want 1485")
+
+print(f"part2 example: {part2(example)} want co,de,ka,ta")
+print(f"part2 actual: {part2(input)} want cc,dz,ea,hj,if,it,kf,qo,sk,ug,ut,uv,wh")