From c64f0360a669b638238f4a470553f448ca8956ff Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Mon, 13 Dec 2021 08:19:19 +0100
Subject: [PATCH] fix 12b

---
 12b.c    | 18 +++++++++++++-----
 Makefile |  3 +++
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/12b.c b/12b.c
index 5be7962..38aaf41 100644
--- a/12b.c
+++ b/12b.c
@@ -51,10 +51,15 @@ char **copy_visited(char **visited, int nvisited)
 	return r;
 }
 
-int find_end(struct node *node, char **visited, int nvisited, bool twice)
+int find_end(struct node *node, char **visited, int nvisited, bool twice, char **path, int npath)
 {
-	if (strcmp(node->key, "end") == 0)
+	if (strcmp(node->key, "end") == 0) {
+		printf("path: ");
+		for (int i = 0; i<npath; i++)
+			printf("%s,", path[i]);
+		printf("\n");
 		return 1;
+	}
 	if (islower(node->key[0])) {
 		for (int i = 0; i<nvisited; i++)
 			if (strcmp(node->key, visited[i]) == 0)
@@ -62,11 +67,13 @@ int find_end(struct node *node, char **visited, int nvisited, bool twice)
 		visited = realloc(visited, sizeof(char *)*(nvisited+1));
 		visited[nvisited++] = node->key;
 	}
+	path = realloc(path, sizeof(char *)*(npath+1));
+	path[npath++] = node->key;
 	int r = 0;
 	for (struct conn *c = node->connections; c != NULL; c = c->hh.next) {
 		if (twice && strcmp(node->key, "start") != 0 && islower(node->key[0]))
-			r += find_end(c->node, copy_visited(visited, nvisited-1), nvisited-1, false);
-		r += find_end(c->node, copy_visited(visited, nvisited), nvisited, twice);
+			r += find_end(c->node, copy_visited(visited, nvisited-1), nvisited-1, false, copy_visited(path, npath), npath);
+		r += find_end(c->node, copy_visited(visited, nvisited), nvisited, twice, copy_visited(path, npath), npath);
 	}
 	free(visited);
 	return r;
@@ -86,5 +93,6 @@ int main()
 			       get_or_create(&graph, toname));
 	}
 
-	printf("%d\n", find_end(get_or_create(&graph, "start"), NULL, 0, true));
+	find_end(get_or_create(&graph, "start"), NULL, 0, true, NULL, 0);
+//	printf("%d\n", find_end(get_or_create(&graph, "start"), NULL, 0, true, NULL, 0));
 }
diff --git a/Makefile b/Makefile
index e656642..50c1a9f 100644
--- a/Makefile
+++ b/Makefile
@@ -13,6 +13,9 @@ clean:
 
 run: $(addprefix run_,$(BINARIES))
 
+run_12b: 12b
+	./12b < 12.txt | sort -u | wc -l
+
 run_%a: %a
 	./$< < $*.txt
 
-- 
2.20.1