Don't infinite loop if we never reach the end point

1 files changed, 5 insertions, 2 deletions

diff --git a/12.c b/12.c
index c647410..42d63d4 100644
--- a/12.c
+++ b/12.c
@@ -136,7 +136,7 @@ main()
 	range[front->x + front->y * cols] |= 0x80;
 
 	// Take steps, widening the search front each iteration.
-	for (steps = 0; 1; ++steps) {
+	for (steps = 0; front != NULL; ++steps) {
 		struct pos * nextfront = NULL;
 		struct pos * loc;
 
@@ -166,7 +166,10 @@ main()
 		front = nextfront;
 	}
 
-	printf("Found end at %d,%d in %d steps\n", front->x, front->y, steps);
+	if (front)
+		printf("Found end at %d,%d in %d steps\n", front->x, front->y, steps);
+	else
+		printf("No end found after %d steps\n", steps);
 
 	pos_free(front);
 	free(range);