equal distribution of sources and sinks

gen.py

@@ -40,8 +40,8 @@ def gettile():
     while True:
         tile = (WIRE, [i for i in range(4) if random.random() < 0.4])
         if len(tile[1]) == 1:
-            if random.random() < 0.2:
-                return (SOURCE, tile[1])
+            if random.random() < 0.1:
+                return (random.choice([SINK,SOURCE]), tile[1])
         elif len(tile[1]) == 0:
             if random.random() < 0.2:
                 return tile
@@ -65,7 +65,8 @@ def joined(puzzle,x1,y1,x2,y2):
     _,ds = puzzle[y1][x1]
     _,ds2 = puzzle[y2][x2]
     diff = (x2-x1,y2-y1)
-    if diff not in [(0,1),(1,0),(0,-1),(-1,0)]: return False
+    if diff not in [(0,1),(1,0),(0,-1),(-1,0)]:
+        return False
     d = directions.index(diff)
     return (d+2)%4 in ds2 and d in ds
 
@@ -111,13 +112,13 @@ def genpuzzle(w,h=None,seed=0):
             while not consistent(puzzle,x,y):
                 puzzle[y][x] = gettile()
     
-    numsinks = (w*h//10) + 1
-    # add linked sink to each source
+    numsinks = (w+h)//5 + 1
+    # add linked source to each sink and vice versa
     for y in range(h):
         for x in range(w):
-            if puzzle[y][x][0] == SOURCE:
+            if puzzle[y][x][0] in [SOURCE,SINK]:
                 x2,y2 = reachable(puzzle,x,y)
-                puzzle[y2][x2] = (SINK,puzzle[y2][x2][1])
+                puzzle[y2][x2] = (3-puzzle[y][x][0],puzzle[y2][x2][1])
     
     for _ in range(numsinks):
         x = random.randint(0,w-1)