day 22 python part 1

day22/sample1.in

@@ -0,0 +1,14 @@
+        ...#
+        .#..
+        #...
+        ....
+...#.......#
+........#...
+..#....#....
+..........#.
+        ...#....
+        .....#..
+        .#......
+        ......#.
+
+10R5L5R10L4R5L5

day22/sample3.in

@@ -0,0 +1,12 @@
+        >>v#    
+        .#v.    
+        #.v.    
+        ..v.    
+...#...v..v#    
+&gt;&gt;&gt;v...<em>&gt;</em>#.&gt;&gt;    
+..#v...#....    
+...&gt;&gt;&gt;&gt;v..#.    
+        ...#....
+        .....#..
+        .#......
+        ......#.

day22/sol.py

@@ -0,0 +1,109 @@
+map = []
+moves = ""
+with open("input") as f:
+    for line in f:
+        if line == "\n":
+            break
+        map.append(line.rstrip("\n"))
+    moves = f.readline().strip()
+
+F = {
+    0: (+1, 0),
+    1: (0, +1),
+    2: (-1, 0),
+    3: (0, -1),
+}
+
+#assert len(set(len(l) for l in map)) == 1
+
+
+class Map:
+    def __init__(self, map):
+        self.map = map
+        self.starts = {}
+        for row in range(len(self.map)):
+            i = 0
+            while self.map[row][i] == ' ':
+                i += 1
+            self.starts[row] = i
+        self.row = 0
+        self.col = self.starts[0]
+        self.face = 0
+
+    def nextTile(self):
+        x,y = self.col, self.row
+        f = self.face
+        # 0 - E
+        # 1 - S
+        # 2 - W
+        # 3 - N
+        dx, dy = F[self.face]
+
+        if dx:
+            x += dx
+            if x < self.starts[y]:
+                x = len(self.map[y])-1
+            elif x >= len(self.map[y]):
+                x = self.starts[y]
+
+        if dy:
+            for _ in range(999):
+                y += dy
+                if y < 0:
+                    y = len(self.map)-1
+                elif y >= len(self.map):
+                    y = 0
+                if x > len(self.map[y]) or self.map[y][x] == ' ':
+                    continue
+                break
+
+        assert self.map[y][x] != ' '
+        return x, y, self.map[y][x]
+
+    def turnLeft(self):
+        self.face = (self.face - 1) % 4
+    def turnRight(self):
+        self.face = (self.face + 1) % 4
+    def walk(self, n):
+        while n > 0:
+            x,y,c = self.nextTile()
+            if c == '#':
+                break
+            self.row = y
+            self.col = x
+            #self.map[y][x] = '>v<^'[self.face]
+            n -= 1
+        print(self.row, self.col)
+
+    def pos(self):
+        return self.row+1, self.col+1
+
+    def score(self):
+        r, c = self.pos()
+        return r*1000 + c *4 + self.face
+
+print(moves)
+
+m = Map(map)
+
+i = 0
+while i < len(moves):
+    if moves[i].isdigit():
+        j = i+1
+        while j < len(moves) and moves[j].isdigit():
+            j += 1
+        n = int(moves[i:j])
+        m.walk(n)
+        i = j
+    elif moves[i] == 'L':
+        m.turnLeft()
+        i += 1
+    elif moves[i] == 'R':
+        m.turnRight()
+        i += 1
+    else:
+        print("invalid move", moves[i], "at", i)
+        i += 1
+
+print(m.row, m.col)
+print(m.score())