whole bunch of days

day01.py

@@ -1,7 +1,13 @@
 import sys
 
+
+def main():
     input = sys.stdin.read().strip().split("\n\n")
     elves = sorted(sum(int(i) for i in elf.split("\n")) for elf in input)
 
     print("Part 1:", elves[-1])
     print("Part 2:", sum(elves[-3:]))
+
+
+if __name__ == "__main__":
+    main()

day02.py

@@ -1,12 +1,18 @@
 import fileinput
 
+
+def main():
     part1, part2 = 0, 0
 
-for line in fileinput.input(mode='rb'):
-    theirs = line[0] - ord('A')
-    ours = line[2] - ord('X')
+    for line in fileinput.input(mode="rb"):
+        theirs = line[0] - ord("A")
+        ours = line[2] - ord("X")
 
         part1 += ours + (ours - theirs + 1) % 3 * 3 + 1
         part2 += ours * 3 + (theirs + ours - 1) % 3 + 1
 
     print(part1, part2)
+
+
+if __name__ == "__main__":
+    main()

day03.py

@@ -1,8 +1,5 @@
 import fileinput
 
-input = [s.strip() for s in fileinput.input()]
-part1, part2 = 0, 0
-
 
 def prio(x):
     if x.islower():
@@ -11,13 +8,16 @@ def prio(x):
         return ord(x) - ord("A") + 27
 
 
+def main():
+    input = [s.strip() for s in fileinput.input()]
+    part1, part2 = 0, 0
+
     for line in input:
         first = set(line[: len(line) // 2])
         second = set(line[len(line) // 2 :])
         both = (first & second).pop()
         part1 += prio(both)
 
-
     for i in range(0, len(input), 3):
         x = set(input[i])
         y = set(input[i + 1])
@@ -26,3 +26,7 @@ for i in range(0, len(input), 3):
         part2 += prio(overlap)
 
     print(part1, part2)
+
+
+if __name__ == "__main__":
+    main()

day04.py

@@ -1,5 +1,7 @@
 import fileinput
 
+
+def main():
     part1, part2 = 0, 0
 
     for line in fileinput.input():
@@ -10,5 +12,8 @@ for line in fileinput.input():
         part1 += (a1 >= b1 and b2 >= a2) or (b1 >= a1 and a2 >= b2)
         part2 += a1 <= b2 and a2 >= b1
 
-
     print(part1, part2)
+
+
+if __name__ == "__main__":
+    main()

day05.py

@@ -1,10 +1,15 @@
 import sys
 import numpy
 
+
+def main():
     inp_stacks, inp_moves = (x.split("\n") for x in sys.stdin.read().split("\n\n", 1))
 
     rows = (line[1::4] for line in inp_stacks[::-1] if "[" in line)
-stacks = [numpy.array([ord(c) for c in x if c != ' '], dtype=numpy.int8) for x in zip(*rows)]
+    stacks = [
+        numpy.array([ord(c) for c in x if c != " "], dtype=numpy.int8)
+        for x in zip(*rows)
+    ]
     stacks1 = numpy.array(stacks)
     stacks2 = numpy.ndarray.copy(stacks1)
 
@@ -24,3 +29,7 @@ for i, line in enumerate(inp_moves):
         stacks2[f] = stacks2[f][:-n]
 
     print("".join(chr(s[-1]) for s in stacks1), "".join(chr(s[-1]) for s in stacks2))
+
+
+if __name__ == "__main__":
+    main()

day06.py

@@ -1,3 +1,8 @@
+def main():
     inp = input().strip()
     print(next(i + 4 for i in range(len(inp)) if len(set(inp[i : i + 4])) == 4))
     print(next(i + 14 for i in range(len(inp)) if len(set(inp[i : i + 14])) == 14))
+
+
+if __name__ == "__main__":
+    main()

day07.py

@@ -0,0 +1,43 @@
+import fileinput
+from collections import defaultdict
+from pprint import pprint
+
+cwd: list[str] = []
+folders: defaultdict[tuple[str, ...], int] = defaultdict(int)
+subdirs: defaultdict[tuple[str, ...], list[str]] = defaultdict(list)
+
+for line in fileinput.input():
+    s = line.split()
+
+    if s[0] == "$":
+        if s[1] == "cd":
+            if s[2] == "..":
+                cwd.pop()
+            elif s[2] == "/":
+                cwd.clear()
+            else:
+                cwd.append(s[2])
+    else:
+        if s[0].isdigit():
+            folders[tuple(cwd)] += int(s[0])
+        elif s[0] == "dir":
+            subdirs[tuple(cwd)].append(s[1])
+
+
+def recur(path: tuple[str, ...]) -> int:
+    # size = folders[path]
+    for subdir in subdirs[path]:
+        folders[path] += recur(path + (subdir,))
+    return folders[path]
+
+
+recur(())
+pprint(folders)
+
+part1 = sum(x for x in folders.values() if x <= 100_000)
+print(part1)
+
+used = folders[()]
+free = 70_000_000 - used
+need_freed = 30_000_000 - free
+print(min(x for x in folders.values() if x > 30_000_000 - free))

day08.py

@@ -0,0 +1,45 @@
+import fileinput
+from pprint import pprint
+
+inp = [[int(y) for y in x.strip()] for x in fileinput.input()]
+inp_ = list(zip(*inp))
+
+part1 = 0
+
+for y in range(1, len(inp) - 1):
+    for x in range(1, len(inp[0]) - 1):
+        x_min_max = max(inp_[x][:y])
+        y_min_max = max(inp[y][:x])
+        x_max_max = max(inp_[x][y + 1 :])
+        y_max_max = max(inp[y][x + 1 :])
+        n = inp[y][x]
+        if n > x_min_max or n > y_min_max or n > x_max_max or n > y_max_max:
+            part1 += 1
+
+part1 += (len(inp) - 1) * 4
+
+
+def viewing_dist(x: int, y: int, dx: int, dy: int) -> int:
+    dist = 0
+    n = inp[y][x]
+    m = 0
+    while n > m:
+        x += dx
+        y += dy
+        if x < 0 or y < 0 or y >= len(inp) or x >= len(inp[0]):
+            break
+        dist += 1
+        m = inp[y][x]
+    return dist
+
+
+scores = []
+for y in range(1, len(inp) - 1):
+    for x in range(1, len(inp[0]) - 1):
+        a = viewing_dist(x, y, 0, -1)
+        b = viewing_dist(x, y, -1, 0)
+        c = viewing_dist(x, y, 1, 0)
+        d = viewing_dist(x, y, 0, 1)
+        scores.append(a * b * c * d)
+
+print(part1, max(scores))

day09.py

@@ -0,0 +1,55 @@
+import fileinput
+
+tx, ty, hx, hy = 0, 0, 0, 0
+
+tail_positions = set()
+
+for line in fileinput.input():
+    dir_, steps = line.split()
+
+    dx, dy = 0, 0
+    match dir_:
+        case "U":
+            dx, dy = 0, 1
+        case "D":
+            dx, dy = 0, -1
+        case "L":
+            dx, dy = -1, 0
+        case "R":
+            dx, dy = 1, 0
+        case _:
+            assert False
+
+    for _ in range(int(steps)):
+        hx_, hy_ = hx, hy
+        hx += dx
+        hy += dy
+        if abs(tx - hx) > 1 or abs(ty - hy) > 1:
+            tx = hx_
+            ty = hy_
+        # for y in range(6, -1, -1):
+        #     for x in range(6):
+        #         if (x, y) == (hx, hy):
+        #             print("H", end="")
+        #         elif (x, y) == (tx, ty):
+        #             print("T", end="")
+        #         elif (x, y) == (0, 0):
+        #             print("s", end="")
+        #         else:
+        #             print(".", end="")
+        #     print()
+        # print()
+        tail_positions.add((tx, ty))
+    print("========")
+
+print(len(tail_positions))
+
+for y in range(10, -1, -1):
+    for x in range(20):
+        if (x, y) == (0, 0):
+            print("s", end="")
+        elif (x, y) in tail_positions:
+            print("#", end="")
+        else:
+            print(".", end="")
+    print()

day10.py

@@ -0,0 +1,33 @@
+import fileinput
+
+reg_x = 1
+cyc = 0
+
+DURATIONS = {"noop": 1, "addx": 2}
+
+part1 = 0
+screen = [0] * 240
+
+for line in fileinput.input():
+    mnem, *args = line.strip().split()
+    d = 0
+
+    for _ in range(DURATIONS[mnem]):
+        cyc += 1
+        if (cyc - 20) % 40 == 0:
+            part1 += cyc * reg_x
+
+        c = (cyc - 1) % 40 + 1
+        if reg_x == c or reg_x + 1 == c or reg_x + 2 == c:
+            screen[cyc - 1] = reg_x
+
+    match mnem:
+        case "noop":
+            pass
+
+        case "addx":
+            reg_x += int(args[0])
+
+print(part1)
+for i in range(0, 240, 40):
+    print("".join("#" if h else " " for h in screen[i : i + 40]))

day11.py

@@ -0,0 +1,76 @@
+import sys
+from pprint import pprint
+from dataclasses import dataclass
+from functools import reduce
+from typing import List
+import operator
+
+
+@dataclass
+class Monke:
+    operation: str
+    param: str
+    divisible_by: int
+    if_true: int
+    if_false: int
+
+
+inputs = [l.split("\n") for l in sys.stdin.read().split("\n\n")]
+monkeys: List[Monke] = []
+
+items = []
+inspections = []
+visited = []
+
+for monkey in inputs:
+    items.append(tuple(int(x) for x in monkey[1][18:].split(", ")))
+    inspections.append(0)
+    visited.append({})
+
+    op, param = monkey[2].split()[4:]
+    divisible_by = int(monkey[3].split()[-1])
+    if_true = int(monkey[4].split()[-1])
+    if_false = int(monkey[5].split()[-1])
+
+    monkeys.append(Monke(op, param, divisible_by, if_true, if_false))
+
+
+def do_round():
+    for m, monke in enumerate(monkeys):
+        # print("Monke", m, monke.items)
+        for item in items[m]:
+            inspections[m] += 1
+
+            # print("  W :=", item)
+
+            param = item if monke.param == "old" else int(monke.param)
+            if monke.operation == "*":
+                item *= param
+                # print("    W *", param, "=", item)
+            elif monke.operation == "+":
+                item += param
+                # print("    W +", param, "=", item)
+            else:
+                assert False
+
+            item //= 3
+            # print("    W / 3 =", item)
+
+            divisible = item % monke.divisible_by == 0
+            # print("    W %", monke.divisible_by, "== 0 =", divisible)
+
+            target = monke.if_true if divisible else monke.if_false
+            # print("    Thrown to", target)
+            items[target] = (*items[target], item)
+
+        items[m] = ()
+
+
+for i in range(20):
+    do_round()
+print(reduce(operator.mul, sorted(inspections)[-2:]))
+
+# for i in range(20, 10_000):
+# if i % 100 == 0: print(i)
+# do_round()
+print(reduce(operator.mul, sorted(inspections)[-2:]))

day12.py

@@ -0,0 +1,60 @@
+import fileinput
+from collections import deque
+
+map = []
+start_pos = None
+end_pos = None
+
+for y, row in enumerate(fileinput.input(mode="rb")):
+    row = row.strip()
+    if not row:
+        continue
+
+    r = []
+    for x, col in enumerate(row):
+        match col:
+            case 83:
+                start_pos = (x, y)
+                r.append(0)
+            case 69:
+                end_pos = (x, y)
+                r.append(25)
+            case _:
+                r.append(col - 97)
+    map.append(r)
+
+assert start_pos is not None
+assert end_pos is not None
+
+part1, part2 = None, None
+
+trace: tuple[tuple[int, int], ...] = ()
+stack = deque([(0, end_pos, trace)])
+visited = set()
+while stack:
+    h_, (x, y), trace = stack.popleft()
+    if x < 0 or x >= len(map[0]) or y < 0 or y >= len(map) or (x, y) in visited:
+        continue
+
+    h = map[y][x]
+    if h - h_ < -1:
+        continue
+
+    if part1 is None and (x, y) == start_pos:
+        part1 = len(trace)
+    if part2 is None and h == 0:
+        part2 = len(trace)
+    if part1 is not None and part2 is not None:
+        break
+
+    visited.add((x, y))
+
+    trace = trace + ((x, y, h),)
+    stack.append((h, (x - 1, y + 0), trace))
+    stack.append((h, (x + 1, y + 0), trace))
+    stack.append((h, (x + 0, y - 1), trace))
+    stack.append((h, (x + 0, y + 1), trace))
+else:
+    assert False
+
+print(part1, part2)

day13.py

@@ -0,0 +1,44 @@
+import fileinput
+import json
+from functools import cmp_to_key
+from typing import Any
+
+
+def main() -> None:
+    pairs = []
+    pair: list[list[Any]] = []
+    packets = [[[2]], [[6]]]
+
+    for line in fileinput.input():
+        if not line.strip():
+            pairs.append(pair)
+            pair = []
+        else:
+            obj = json.loads(line)
+            pair.append(obj)
+            packets.append(obj)
+
+    pairs.append(pair)
+
+    def cmp(xs: list[Any] | int, ys: list[Any] | int) -> int:
+        if isinstance(xs, int) and isinstance(ys, int):
+            return (xs > ys) - (xs < ys)
+
+        if isinstance(xs, int):
+            xs = [xs]
+        if isinstance(ys, int):
+            ys = [ys]
+
+        for x, y in zip(xs, ys):
+            if result := cmp(x, y):
+                return result
+
+        return (len(xs) > len(ys)) - (len(xs) < len(ys))
+
+    print(sum(i + 1 for i, (xs, ys) in enumerate(pairs) if cmp(xs, ys) == -1))
+
+    packets.sort(key=cmp_to_key(cmp))
+    print((packets.index([[2]]) + 1) * (packets.index([[6]]) + 1))
+
+
+main()