From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Sun, 22 May 2005 11:45:20 +0000 (+0000)
Subject: Special case in dead-end checking which prevents the solver falling
X-Git-Url: https://git.distorted.org.uk/~mdw/sgt/puzzles/commitdiff_plain/9535138a690f4efdc0b38a422f45fcfdaf887c80

Special case in dead-end checking which prevents the solver falling
over on a grid containing a 0 (completely blank) tile. This can't
happen in self-generated grids, but can happen if you type in a grid
from another Net implementation. Previously, the solver would notice
(technically correctly!) that a completely blank tile connects to no
other tiles and thus forms an isolated subgraph, and would therefore
complain that no orientation of that tile could possibly yield a
valid solution...


git-svn-id: svn://svn.tartarus.org/sgt/puzzles@5828 cda61777-01e9-0310-a592-d414129be87e
---

diff --git a/net.c b/net.c
index b5134a9..5037c9b 100644
--- a/net.c
+++ b/net.c
@@ -657,7 +657,7 @@ static int net_solver(int w, int h, unsigned char *tiles,
 		     * dead ends of size 2 and 3 forms a subnetwork
 		     * with a total area of 6, not 5.)
 		     */
-		    if (deadendtotal+1 < area)
+		    if (deadendtotal > 0 && deadendtotal+1 < area)
 			valid = FALSE;
 		} else if (nnondeadends == 1) {
 		    /*