Improve lib and use it to solve 3 and 17.

lib.py

@@ -7,16 +7,6 @@ NUMBERS = string.digits
 LETTERS_LOWER = string.ascii_lowercase
 LETTERS_UPPER = string.ascii_uppercase
 
-UP = (-1, 0)
-DOWN = (1, 0)
-RIGHT = (0, 1)
-LEFT = (0, -1)
-
-NORTH = UP
-SOUTH = DOWN
-EAST = RIGHT
-WEST = LEFT
-
 INF = float("inf")
 fst = lambda l: l[0]
 snd = lambda l: l[1]
@@ -33,6 +23,15 @@ def add2(a: tuple[int, int], b: tuple[int, int]) -> tuple[int, int]:
     return (a[0] + b[0], a[1] + b[1])
 
 class Grid2D:
+    N = (-1, 0)
+    E = (0, 1)
+    S = (1, 0)
+    W = (0, -1)
+    NW = (-1, -1)
+    NE = (-1, 1)
+    SE = (1, 1)
+    SW = (1, -1)
+
     def __init__(self, text: str):
         lines = [line for line in text.splitlines() if line.strip() != ""]
         self.grid = list(map(list, lines))
@@ -64,13 +63,10 @@ class Grid2D:
                 for col_i in range(self.n_cols)]
 
     def find(self, chars: str) -> list[tuple[int, int]]:
-        r = []
-        for row_i in range(self.n_rows):
-            for col_i in range(self.n_cols):
-                c = (row_i, col_i)
-                if self[c] in chars:
-                    r.append(c)
-        return r
+        return [c for c in self.all_coords() if self[c] in chars]
+
+    def find_not(self, chars: str) -> list[tuple[int, int]]:
+        return [c for c in self.all_coords() if self[c] not in chars]
 
     def all_coords(self) -> list[tuple[int, int]]:
         return [(row_i, col_i)
@@ -89,17 +85,27 @@ class Grid2D:
         row, col = pos
         return row >= 0 and row < self.n_rows and col >= 0 and col < self.n_cols
 
+    def __contains__(self, pos: tuple[int, int]) -> bool:
+        return self.contains(pos)
+
     def neighbors_ort(self, pos: tuple[int, int]) -> list[tuple[int, int]]:
-        ort_rel = [(-1, 0), (0, 1), (1, 0), (0, -1)]
-        return [add2(pos, off) for off in ort_rel if self.contains(add2(pos, off))]
+        return [add2(pos, off) for off in self.dirs_ort() if self.contains(add2(pos, off))]
 
     def neighbors_vert(self, pos: tuple[int, int]) -> list[tuple[int, int]]:
-        ort_vert = [(-1, -1), (-1, 1), (1, 1), (1, -1)]
-        return [add2(pos, off) for off in ort_vert if self.contains(add2(pos, off))]
+        return [add2(pos, off) for off in self.dirs_vert() if self.contains(add2(pos, off))]
 
     def neighbors_adj(self, pos: tuple[int, int]) -> list[tuple[int, int]]:
         return self.neighbors_ort(pos) + self.neighbors_vert(pos)
 
+    def flip_ort(self, pos: tuple[int, int]) -> tuple[int, int]:
+        return (-pos[0], -pos[1])
+
+    def dirs_ort(self) -> list[tuple[int, int]]:
+        return [self.N, self.E, self.S, self.W]
+
+    def dirs_vert(self) -> list[tuple[int, int]]:
+        return [self.NE, self.SE, self.SW, self.NW]
+
     def print(self):
         for r in self.rows():
             print("".join(r))