day 22 python part 2

day22/sol.py

@@ -16,7 +16,6 @@ F = {
 
 #assert len(set(len(l) for l in map)) == 1
 
-
 class Map:
     def __init__(self, map):
         self.map = map
@@ -30,14 +29,79 @@ class Map:
         self.col = self.starts[0]
         self.face = 0
 
-    def nextTile(self):
+        #   9'
-        x,y = self.col, self.row
+        #   1 2
-        f = self.face
+        # \ 4 \
+        # 6 7
+        # 9 \
+        self.region_map = {
+            #   R      D      L     U
+            1: [(2,0), (4, 0), (6,2), (9, 1)],
+            4: [(2,-1), (7,0), (6,-1), (1, 0)],
+            7: [(2,2), (9,+1), (6,0), (4,0)],
+            6: [(7,0), (9,0), (1,2), (4,+1)],
+            9: [(7,-1), (2,0), (1,-1), (6,0)],
+            2: [(7,2), (4,+1), (1, 0), (9,0)],
+        }
+
+        ok = True
+        for f in range(4):
+            for r in self.region_map:
+                orig = (r,f)
+                s = repr(orig)
+                for _ in range(4):
+                    r, h = self.region_map[r][f]
+                    f = (f+h)%4
+                    s += "-> {} {}".format(r, f)
+                if (r,f) != orig:
+                    print("!!", s)
+                    ok = False
+        assert ok, "region topography failure"
+
+    def nextTile(self, x, y, face):
         # 0 - E
         # 1 - S
         # 2 - W
         # 3 - N
-        dx, dy = F[self.face]
+        dx, dy = F[face]
+        r = self.region(x,y)
+        if 0 <= (x%50 + dx) < 50 and 0 <= (y%50 + dy) < 50:
+            x, y = x+dx, y+dy
+        else:
+            new_r, rotate = self.region_map[r][face]
+            x = (x+dx) % 50
+            y = (y+dy) % 50
+
+            if rotate == 0:
+                pass
+            elif rotate == -1:
+                x, y = y, 50-x-1
+            elif rotate == 1:
+                x, y = 50-y-1, x
+            elif rotate == 2:
+                x, y = 50-x-1, 50-y-1
+            x, y = self.in_region(x, y, new_r)
+            face = (face + rotate) % 4
+        c = self.map[y][x]
+        assert c != ' '
+        return x, y, face, c
+
+    @staticmethod
+    def in_region(x, y, r):
+        """returns the absolute coords if the local (x,y) in region r"""
+        x %= 50
+        y %= 50
+        rx = r % 3
+        ry = r // 3
+        return (rx*50 + x), (ry*50 + y)
+
+    @staticmethod
+    def region(x, y):
+        return y//50 * 3 + x//50
+
+    def warp(x,y,face):
+        r = self.region(x,y)
+        s = 0
 
         if dx:
             x += dx
@@ -66,14 +130,16 @@ class Map:
         self.face = (self.face + 1) % 4
     def walk(self, n):
         while n > 0:
-            x,y,c = self.nextTile()
+            x,y,f,c = self.nextTile(self.col, self.row, self.face)
             if c == '#':
                 break
+                pass#break
             self.row = y
             self.col = x
+            self.face = f
             #self.map[y][x] = '>v<^'[self.face]
             n -= 1
-        print(self.row, self.col)
+        print(self.row+1, self.col+1)
 
     def pos(self):
         return self.row+1, self.col+1
@@ -86,6 +152,11 @@ print(moves)
 
 m = Map(map)
 
+for _ in range(4):
+    #m.walk(50)
+    print("---")
+
+#blah
 i = 0
 while i < len(moves):
     if moves[i].isdigit():