advent_of_code_2021

commit 4a8670dc62efc98f30b853c6c4c3753bd83e3e1b
parent 04d38c9e24dc4c40c3668400ea86389961920c3f
Author: Eamon Caddigan <eamon.caddigan@gmail.com>
Date:   Sat, 18 Dec 2021 20:42:35 -0500

Solution to day 18, part 2

Diffstat:
A
day18_part2.py
 | 
37
+++++++++++++++++++++++++++++++++++++

1 file changed, 37 insertions(+), 0 deletions(-)
diff --git a/day18_part2.py b/day18_part2.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+"""Advent of Code 2021, day 18 (part 2): Snailfish math
+Snilfish math!"""
+
+
+from typing import List
+from itertools import permutations
+from day18_part1 import (EXAMPLE_INPUT,
+                         MathNode,
+                         parse_input,
+                         add_nodes,
+                         find_magnitude)
+from utils import get_puzzle_input
+
+def find_pairwise_sums(input_nodes: List[MathNode]) -> List[int]:
+    """Find the list of every pair of nodes in the list (in both orderings)"""
+    pairwise_sums = []
+    for node_1, node_2 in permutations(input_nodes, 2):
+        pairwise_sums.append(
+            find_magnitude(
+                add_nodes(node_1, node_2)
+            )
+        )
+    return pairwise_sums
+
+def solve_puzzle(input_string: str) -> int:
+    """Return the numeric solution to the puzzle"""
+    return max(find_pairwise_sums(parse_input(input_string)))
+
+def main() -> None:
+    """Run when the file is called as a script"""
+    assert solve_puzzle(EXAMPLE_INPUT) == 3993
+    print("Magnitude of the highest possible sum of pairs:",
+          solve_puzzle(get_puzzle_input(18)))
+
+if __name__ == "__main__":
+    main()