2017/day12.py

@@ -1,42 +0,0 @@
-from collections import defaultdict
-
-with open("input/day12.txt") as f:
-    input = f.read()
-
-neighbors = defaultdict(set)
-
-for line in input.splitlines():
-    a, bs = line.split(" <-> ")
-    for b in bs.split(", "):
-        neighbors[a].add(b)
-        neighbors[b].add(a)
-
-
-def connected(start, neighbors):
-    queue = [start]
-    seen = set()
-    while queue:
-        node = queue.pop(0)
-        if node in seen:
-            continue
-
-        seen.add(node)
-        queue.extend(neighbors[node])
-    return seen
-
-
-def groups(neighbors) -> int:
-    seeds = set(neighbors.keys())
-    count = 0
-
-    while seeds:
-        start = seeds.pop()
-        seen = connected(start, neighbors)
-        seeds.difference_update(seen)
-        count += 1
-
-    return count
-
-
-print(len(connected("0", neighbors)))
-print(groups(neighbors))

2017/day13.py

@@ -1,99 +0,0 @@
-from math import lcm
-from dataclasses import dataclass
-
-with open("input/day13.txt") as f:
-    input = f.read()
-
-scanners: dict[int, int] = {}
-
-for line in input.splitlines():
-    parts = line.split(": ")
-    d, r = int(parts[0]), int(parts[1])
-
-    assert d not in scanners, "no overlapping scanners"
-    scanners[d] = r
-
-
-def part1(scanners):
-    severity = 0
-    for d in range(max(scanners.keys()) + 1):
-        r = scanners.get(d)
-        if r is None:
-            continue
-
-        assert r > 1, r
-        cycle = (r - 1) * 2
-        pos = d % cycle
-        if pos == 0:
-            severity += d * r
-    return severity
-
-
-def is_safe(scanners, delay):
-    for depth in range(max(scanners.keys()) + 1):
-        r = scanners.get(depth)
-        if r is None:
-            continue
-
-        assert r > 1, r
-        cycle = (r - 1) * 2
-        pos = (delay + depth) % cycle
-        if pos == 0:
-            return False
-    return True
-
-
-@dataclass
-class Scanner:
-    depth: int
-    cycle: int
-
-
-@dataclass(order=True)
-class Candidate:
-    delay: int
-    increment: int
-
-    def __init__(self, delay: int, increment: int):
-        self.delay = delay % increment
-        self.increment = increment
-
-    def __hash__(self):
-        return hash((self.delay % self.increment, self.increment))
-
-    def scale(self, scalar: int) -> set["Candidate"]:
-        res = set()
-        increment = self.increment * scalar
-        for i in range(scalar + 1):
-            res.add(Candidate(self.delay + i * self.increment, increment))
-        return res
-
-    def __str__(self):
-        return f"{self.delay} + k * {self.increment}"
-
-
-def part2(scanner_map: dict[int, int]):
-    scanners: list[Scanner] = []
-    for depth in range(max(scanner_map.keys()) + 1):
-        r = scanner_map.get(depth)
-        if r is None:
-            continue
-        cycle = (r - 1) * 2
-        scanners.append(Scanner(depth, cycle))
-
-    candidates = {Candidate(0, 1)}
-    for s in scanners:
-        next: set[Candidate] = set()
-        for c in candidates:
-            scalar = lcm(c.increment, s.cycle) // c.increment
-            for n in c.scale(scalar):
-                if (n.delay + s.depth) % s.cycle:
-                    next.add(n)
-
-        candidates = next
-
-    return min(c.delay for c in candidates)
-
-
-print(part1(scanners))
-print(part2(scanners))