Day 13

13.py

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+#!/usr/bin/python
+
+from collections import defaultdict
+from itertools import permutations
+import re
+
+pattern = re.compile('^(.*) would (lose|gain) ([0-9]+) happiness .* next to (.*).')
+happiness = defaultdict(int)
+names = set()
+
+with open('13.txt', 'r') as file:
+    for line in file.readlines():
+        first, type, value, second = pattern.match(line).groups()
+        happiness[frozenset((first, second))] += (-1 if type == 'lose' else 1) * int(value)
+        names.add(first)
+
+
+def get_score(order):
+    return sum(happiness[frozenset(pair)] for pair in zip(order, order[1:] + [order[0]]))
+
+
+def find_best(people):
+    remaining = people.copy()
+    first = remaining.pop()
+    return max(get_score([first] + list(order)) for order in permutations(remaining))
+
+
+print(find_best(names))
+print(find_best(names.union("me")))

13.txt

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+Alice would gain 2 happiness units by sitting next to Bob.
+Alice would gain 26 happiness units by sitting next to Carol.
+Alice would lose 82 happiness units by sitting next to David.
+Alice would lose 75 happiness units by sitting next to Eric.
+Alice would gain 42 happiness units by sitting next to Frank.
+Alice would gain 38 happiness units by sitting next to George.
+Alice would gain 39 happiness units by sitting next to Mallory.
+Bob would gain 40 happiness units by sitting next to Alice.
+Bob would lose 61 happiness units by sitting next to Carol.
+Bob would lose 15 happiness units by sitting next to David.
+Bob would gain 63 happiness units by sitting next to Eric.
+Bob would gain 41 happiness units by sitting next to Frank.
+Bob would gain 30 happiness units by sitting next to George.
+Bob would gain 87 happiness units by sitting next to Mallory.
+Carol would lose 35 happiness units by sitting next to Alice.
+Carol would lose 99 happiness units by sitting next to Bob.
+Carol would lose 51 happiness units by sitting next to David.
+Carol would gain 95 happiness units by sitting next to Eric.
+Carol would gain 90 happiness units by sitting next to Frank.
+Carol would lose 16 happiness units by sitting next to George.
+Carol would gain 94 happiness units by sitting next to Mallory.
+David would gain 36 happiness units by sitting next to Alice.
+David would lose 18 happiness units by sitting next to Bob.
+David would lose 65 happiness units by sitting next to Carol.
+David would lose 18 happiness units by sitting next to Eric.
+David would lose 22 happiness units by sitting next to Frank.
+David would gain 2 happiness units by sitting next to George.
+David would gain 42 happiness units by sitting next to Mallory.
+Eric would lose 65 happiness units by sitting next to Alice.
+Eric would gain 24 happiness units by sitting next to Bob.
+Eric would gain 100 happiness units by sitting next to Carol.
+Eric would gain 51 happiness units by sitting next to David.
+Eric would gain 21 happiness units by sitting next to Frank.
+Eric would gain 55 happiness units by sitting next to George.
+Eric would lose 44 happiness units by sitting next to Mallory.
+Frank would lose 48 happiness units by sitting next to Alice.
+Frank would gain 91 happiness units by sitting next to Bob.
+Frank would gain 8 happiness units by sitting next to Carol.
+Frank would lose 66 happiness units by sitting next to David.
+Frank would gain 97 happiness units by sitting next to Eric.
+Frank would lose 9 happiness units by sitting next to George.
+Frank would lose 92 happiness units by sitting next to Mallory.
+George would lose 44 happiness units by sitting next to Alice.
+George would lose 25 happiness units by sitting next to Bob.
+George would gain 17 happiness units by sitting next to Carol.
+George would gain 92 happiness units by sitting next to David.
+George would lose 92 happiness units by sitting next to Eric.
+George would gain 18 happiness units by sitting next to Frank.
+George would gain 97 happiness units by sitting next to Mallory.
+Mallory would gain 92 happiness units by sitting next to Alice.
+Mallory would lose 96 happiness units by sitting next to Bob.
+Mallory would lose 51 happiness units by sitting next to Carol.
+Mallory would lose 81 happiness units by sitting next to David.
+Mallory would gain 31 happiness units by sitting next to Eric.
+Mallory would lose 73 happiness units by sitting next to Frank.
+Mallory would lose 89 happiness units by sitting next to George.