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y2023/p01.py

@@ -0,0 +1,18 @@
+import re
+
+
+def solve(text, digits):
+    tot = 0
+    rgx = '(' + '|'.join(digits) + ')'
+    rgx = f'(?={rgx})'  # allow overlapping matches
+    for ln in text.splitlines():
+        ns = [digits.get(s, s) for s in re.findall(rgx, ln)]
+        tot += 10 * ns[0] + ns[-1]
+    print(tot)
+
+
+text = open(0).read()
+xs = {v: k for k, v in enumerate('0123456789')}
+ys = {v: k for k, v in enumerate('zero one two three four five six seven eight nine'.split())}
+solve(text, xs)
+solve(text, xs | ys)

y2023/p02.py

@@ -0,0 +1,16 @@
+import math
+import re
+
+
+text = open(0).read()
+ans1 = 0
+ans2 = 0
+for idx, line in enumerate(text.splitlines(), 1):
+    parse = lambda string: {v: int(k) for k, v in re.findall(r'(\d+) (r|g|b)', string)}
+    games = [parse(game) for game in re.findall(r'[^:;]+', line)[1:]]
+    rgb = [max(game.get(k, 0) for game in games) for k in 'rgb']
+    ans1 += all(qty <= lim for qty, lim in zip(rgb, [12, 13, 14])) and idx
+    ans2 += math.prod(rgb)
+print(ans1)
+print(ans2)
+

y2023/p03.py

@@ -0,0 +1,32 @@
+import math
+import collections
+import itertools
+import re
+
+
+text = open(0).read()
+grid = collections.defaultdict(str) | {
+    (x, y): cell
+    for y, line in enumerate(text.splitlines())
+    for x, cell in enumerate(line)
+}
+parts = collections.defaultdict(list)
+
+ans1 = 0
+for y, ln in enumerate(text.splitlines()):
+    ys = [y - 1, y, y + 1]
+    for match in re.finditer(r'\d+', ln):
+        N = int(match.group(0))
+        xs = list(range(match.start() - 1, match.end() + 1))
+
+        sub = {(x, y): grid[x, y] for x in xs for y in ys}
+        if set(sub.values()) - set('0123456789\n.'):
+            ans1 += N
+
+        for key, value in sub.items():
+            if value == '*':
+                parts[key].append(N)
+print(ans1)
+
+ans2 = sum(math.prod(values) for values in parts.values() if len(values) == 2)
+print(ans2)

y2023/p04.py

@@ -0,0 +1,13 @@
+text = open(0).read()
+
+cards = []
+for line in text.splitlines():
+    ns, ms = [[int(n) for n in line.strip().split()] for line in line.split(':')[1].split('|')]
+    cards.append(len(set(ns) & set(ms)))
+print(sum(2 ** (n - 1) for n in cards if n))
+
+counter = [1 for _ in cards]
+for i, n in enumerate(cards):
+    for j in range(i + 1, i + 1 + n):
+        counter[j] += counter[i]
+print(sum(counter))

y2023/p05.py

@@ -0,0 +1,34 @@
+import itertools
+import pathlib
+import re
+
+
+text = open(0).read()
+[seed], *groups = [[[int(n) for n in ln.split()] for ln in group.split(':')[1].strip().splitlines()] for group in text.split('\n\n')]
+
+
+def forward(n):
+    for group in groups:
+        n = next((n + (b - a) for b, a, c in group if a <= n < a + c), n)
+    return n
+
+
+ans1 = min([forward(n) for n in seed])
+print(ans1)
+
+ns = []
+for group in reversed(groups):
+    ns += [n for b, a, c in group for n in [b, b + c - 1]]
+    ns = [next((n - (b - a) for b, a, c in group if b <= n < b + c), n) for n in ns]
+ans2 = min(forward(n) for n in ns if any(a <= n < a + b for a, b in zip(seed[::2], seed[1::2])))
+print(ans2)
+
+
+# old method, slow
+def backward(n):
+    for group in groups:
+        n = next((n - (b - a) for b, a, c in group if b <= n < b + c), n)
+    return n
+
+pairs = [(a, a + b) for a, b in zip(seed[::2], seed[1::2])]
+next(n for n in itertools.count(ans2) if any(a <= backward(n) < a + b for a, b in pairs))