diff --git a/day03.py b/day03.py
index da67229..7a852d8 100644
--- a/day03.py
+++ b/day03.py
@@ -1,5 +1,7 @@
 #!/usr/bin/env python3
 
+from functools import cache
+
 up    = lambda v: (v[0], v[1] + 1)
 down  = lambda v: (v[0], v[1] - 1)
 left  = lambda v: (v[0] - 1, v[1])
@@ -11,20 +13,12 @@ moves = {'U' : up,
          'R' : right
         }
 
-def memoize(f):
-    cache = dict()
-    def memf(path):
-        if path not in cache:
-            cache[path] = f(path)
-        return cache[path]
-    return memf
-
 def iterate(f, x, N):
     for i in range(N):
         yield x
         x = f(x)
 
-@memoize
+@cache
 def lines(path):
     pos = (0, 0)
     r = []
diff --git a/day07.py b/day07.py
index adda838..9927ada 100644
--- a/day07.py
+++ b/day07.py
@@ -2,14 +2,15 @@
 
 from intcode import preproc
 from itertools import permutations
-from lib import memoize, last
+from lib import last
+from functools import cache
 
 stack_size = 5
 fst_amp_input = 0
 
 
 def partI(amp):
-    run_amp = memoize(lambda *args : last(amp(*args)))
+    run_amp = cache(lambda *args : last(amp(*args)))
 
     phase_range = range(stack_size)
     best = 0 
diff --git a/day08.py b/day08.py
index dfa60d2..7bfb20e 100644
--- a/day08.py
+++ b/day08.py
@@ -1,14 +1,13 @@
 #!/usr/bin/env python3
 
+from lib import Color
+
 ZERO, ONE, TWO = "012"
 
-BLACK = 0
-WHITE = 1
-
-color = {WHITE : u"\u2B1C",
-         BLACK : u"\u2B1B"
-        }
+BLACK = ZERO 
+WHITE = ONE 
 
+encode = {WHITE : Color.WHITE, BLACK : Color.BLACK}
 
 class Image:
     def __init__(self, data, w, h):
@@ -31,7 +30,7 @@ class Image:
         return '\n'.join(image[i:i+w] for i in range(0, len(image), w))
 
     def __str__(self):
-        return repr(self).replace(ZERO, color[BLACK]).replace(ONE, color[WHITE])
+        return repr(self).replace(BLACK, encode[BLACK]).replace(WHITE, encode[WHITE])
 
 
 
diff --git a/day10.py b/day10.py
index 83649c4..3831899 100644
--- a/day10.py
+++ b/day10.py
@@ -1,64 +1,33 @@
 #!/usr/bin/env python3
 
-from math import gcd
 from fractions import Fraction
 from itertools import product
-from functools import total_ordering
 from collections import defaultdict
+from lib import vector
 
 ASTEROID = '#'
 
-def zrange(x, y, step):
-    if x == y == step == 0:
-        def yzero():
-            while True:
-                yield 0
-        return yzero()
-    return range(x, y, step)
-
 def angle(v):
-        if v.x == 0:
-            return (2 * int(v.y > 0), 0)
-        halve = 1 if v.x > 0 else 3
-        return (halve, Fraction(v.y, v.x))
+    x, y = v
+    if x == 0:
+        return (2 * int(y > 0), 0)
+    halve = 1 if x > 0 else 3
+    return (halve, Fraction(y, x))
 
 def rebase(base, vectors):
     return (v - base for v in vectors if v != base)
 
-@total_ordering
-class Vector:
-    def __init__(self, x, y):
-        self.x = x
-        self.y = y
-    def __add__(self, other):
-        return Vector(self.x + other.x, self.y + other.y)
-    def __sub__(self, other):
-        return self + Vector(-other.x, -other.y)
-    def __eq__(self, other):
-        return self.x == other.x and self.y == other.y
-    def __lt__(self, other):
-        return (self.x**2 + self.y**2) < (other.x**2 + other.y**2)
-    def __str__(self):
-        return str((self.x, self.y))
-    def __repr__(self):
-        return str(self)
-
-class Map:
-    def __init__(self, map):
-        self.map = map
-
-    def __getitem__(self, v):
-        return self.map[v.y][v.x]
-
+class Map(list):
     def __str__(self):
         return '\n'.join(self.map)
 
     def is_asteroid(self, v):
-        return self[v] == ASTEROID
+        x, y = v
+        return self[y][x] == ASTEROID
 
     def vectors(self):
-        X, Y = len(self.map[0]), len(self.map)
-        return (Vector(x, y) for x, y in product(range(X), range(Y)))
+        X, Y = len(self[0]), len(self)
+        return (vector(v) for v in product(range(X), range(Y)))
 
     def asteroid_vectors(self):
         return filter(lambda v: self.is_asteroid(v), self.vectors())
@@ -94,8 +63,8 @@ def partI(packed):
 
 def partII(packed):
     asteroid_map, asteroid, _ = packed
-    v = asteroid_map.vaporize_seq(asteroid)[199]
-    return 100*v.x + v.y
+    x, y = asteroid_map.vaporize_seq(asteroid)[199]
+    return 100*x + y
 
 from main import Tests
 
diff --git a/lib.py b/lib.py
index 102846a..bf78665 100644
--- a/lib.py
+++ b/lib.py
@@ -4,6 +4,11 @@ import itertools
 from collections import deque
 from enum import Enum
 
+# Random definitons ---------------------------------------
+class Color:
+    WHITE = u"\u2B1C"
+    BLACK = u"\u2B1B"
+
 # Iterator recipes ----------------------------------------
 def last(iterator):
     """Exhausts an iterator and returns its last element."""
@@ -30,6 +35,7 @@ class defaultlist(list):
             return self.val_factory() 
         return super().__getitem__(i)
 
+
 # Basic linear algebra ------------------------------------
 class vector(tuple):
     """Vector class. Convert iterator to vector."""