2024.07

challenges/2024/07-bridgeRepair/README.md

@@ -0,0 +1,14 @@
+# [Day 7: Bridge Repair](https://adventofcode.com/2024/day/7)
+
+Part 1 is:
+* greater than 450054910499
+
+Before optimisation (pregenerating then testing operator combiantions using `itertools.product("*+|", length=n)`), runtime looks something like this:
+
+```
+Part 1: min 0.2671 seconds, max 0.2818 seconds, avg 0.2755
+Part 2: min 23.2387 seconds, max 24.8753 seconds, avg 23.8805
+```
+
+It also appeared that using string concatenation as opposed to pure mathematical functions for the concatenation operator was marginally faster in Python.
+

challenges/2024/07-bridgeRepair/main.py

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+import sys
+import itertools
+from typing import Iterable
+import math
+
+
+def parse(instr: str) -> list[tuple[int, list[int]]]:
+    res = []
+    for line in instr.splitlines():
+        spa, spb = line.split(": ")
+        res.append(
+            (int(spa), list(map(int, spb.split(" ")))),
+        )
+    return res
+
+
+def evaluate(ns: list[int], ops: Iterable[str]):
+    acc = ns[0]
+    for i, (v, op) in enumerate(zip(ns[1:], ops)):
+        if op == "*":
+            acc *= v
+        elif op == "+":
+            acc += v
+        elif op == "|":
+            acc = (acc * (10 ** int(math.log10(v) + 1))) + v
+        else:
+            raise ValueError(f"unknown operation {op}")
+    return acc
+
+
+def one(instr: str):
+    cases = parse(instr)
+
+    cached_ops = {}
+
+    n = 0
+    for (target, numbers) in cases:
+        num_ops = len(numbers) - 1
+        if num_ops not in cached_ops:
+            cached_ops[num_ops] = tuple(itertools.product("+*", repeat=num_ops))
+
+        for ops in cached_ops[num_ops]:
+            v = evaluate(numbers, ops)
+            if v == target:
+                n += v
+                break
+
+    return n
+
+
+def two(instr: str):
+    cases = parse(instr)
+
+    cached_ops = {}
+
+    n = 0
+    for (target, numbers) in cases:
+        num_ops = len(numbers) - 1
+        if num_ops not in cached_ops:
+            cached_ops[num_ops] = tuple(itertools.product("+*|", repeat=num_ops))
+
+        for ops in cached_ops[num_ops]:
+            v = evaluate(numbers, ops)
+            if v == target:
+                n += v
+                break
+
+    return n
+
+
+def _debug(*args, **kwargs):
+    kwargs["file"] = sys.stderr
+    print(*args, **kwargs)
+
+
+if __name__ == "__main__":
+    if len(sys.argv) < 2 or sys.argv[1] not in ["1", "2"]:
+        print("Missing day argument", file=sys.stderr)
+        sys.exit(1)
+    inp = sys.stdin.read().strip()
+    if sys.argv[1] == "1":
+        print(one(inp))
+    else:
+        print(two(inp))

challenges/2024/07-bridgeRepair/tests.json

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+{
+    "1": [
+        {
+            "is": "3749",
+            "input": "190: 10 19\n3267: 81 40 27\n83: 17 5\n156: 15 6\n7290: 6 8 6 15\n161011: 16 10 13\n192: 17 8 14\n21037: 9 7 18 13\n292: 11 6 16 20\n"
+        }
+    ],
+    "2": [
+        {
+            "is": "11387",
+            "input": "190: 10 19\n3267: 81 40 27\n83: 17 5\n156: 15 6\n7290: 6 8 6 15\n161011: 16 10 13\n192: 17 8 14\n21037: 9 7 18 13\n292: 11 6 16 20\n"
+        }
+    ]
+}

challenges/2024/benchmarks.jsonl

@@ -10,3 +10,5 @@
 {"day": 5, "part": 2, "runner": "py", "min": 0.02507805824279785, "max": 0.03197765350341797, "avg": 0.027084295749664308, "n": 100}
 {"day": 6, "part": 1, "runner": "py", "min": 0.05790352821350098, "max": 0.06762170791625977, "avg": 0.061776439348856606, "n": 6}
 {"day": 6, "part": 2, "runner": "py", "min": 15.881408452987671, "max": 17.086341857910156, "avg": 16.64130985736847, "n": 6}
+{"day": 7, "part": 1, "runner": "py", "min": 0.26709485054016113, "max": 0.28178858757019043, "avg": 0.2754525661468506, "n": 5}
+{"day": 7, "part": 2, "runner": "py", "min": 23.23872661590576, "max": 24.87530255317688, "avg": 23.880544805526732, "n": 5}