From 1c299059bca4b411d944bb9626f23b5d428ae548 Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Fri, 2 Sep 2011 18:19:58 +0200
Subject: [PATCH] Digit: Calculating possible moves...

---
 ucw/digit.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/ucw/digit.c b/ucw/digit.c
index 6331782..7cc9867 100644
--- a/ucw/digit.c
+++ b/ucw/digit.c
@@ -10,7 +10,8 @@
 #include <string.h>
 
 #define MATCHES 5
-#define SIZE (2*MATCHES+3)
+#define SIZE (2*MATCHES+5)
+/* +5, because possible_moves() sometimes needs to represent a disconnected 5-match configuration with 1 gap */
 
 typedef char conf[SIZE][SIZE];
 
@@ -191,6 +192,7 @@ static void generate(void)
 		  struct state *t = lookup(to);
 		  if (!t)
 		    {
+		      ASSERT(wi < MAXSTATES);
 		      t = &states[wi++];
 		      norm(to, t->c);
 		      t->matches = s->matches+1;
@@ -212,8 +214,55 @@ static void generate(void)
     }
 }
 
+static void possible_moves(void)
+{
+  puts("\n=== POSSIBLE MOVES ===\n\n");
+
+  for (int i=0; i<wi; i++)
+    states[i].from = 0;
+
+  for (int i=0; i<wi; i++)
+    {
+      struct state *s = &states[i];
+      if (s->matches < MATCHES)
+	continue;
+      conf c;
+      memcpy(c, s->c, sizeof(conf));
+
+      printf("### State %d ###\n", s->id);
+      print(s->c);
+
+      int neighbors = 0;
+      for (int j=0; j<SIZE; j++)
+	for (int k=0; k<SIZE; k++)
+	  if (s->c[j][k])
+	    {
+	      c[j][k] = 0;
+	      for (int p=0; p<SIZE; p++)
+		for (int q=0; q<SIZE; q++)
+		  if (!c[p][q] && (p != j || q != k) && has_neighbor(c, p, q))
+		    {
+		      c[p][q] = 1;
+		      struct state *t = lookup(c);
+		      if (t && t != s && t->from != s->id)
+			{
+			  t->from = s->id;
+			  // printf("-> state %d\n", t->id);
+			  // print(t->c);
+			  neighbors++;
+			}
+		      c[p][q] = 0;
+		    }
+	      c[j][k] = 1;
+	    }
+
+      printf("=> %d neighbors\n\n", neighbors);
+    }
+}
+
 int main(void)
 {
   generate();
+  possible_moves();
   return 0;
 }
-- 
2.39.2