AoC 2023 day 8

8/a.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+# Copyright 2023 Síle Ekaterin Liszka
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+from itertools import cycle
+
+insn = ''
+data = []
+
+with open('input.txt', mode='r') as f:
+	data = f.readlines()
+
+	insn = cycle(data[0][:-1])
+	data = data[2:]
+
+nodes = {}
+
+for line in data:
+	name, dest = line.split(' = ', maxsplit=1)
+	left, right = dest[1:-2].split(', ', maxsplit=1)
+	nodes[name] = (left, right)
+
+move = {'L': 0, 'R': 1}
+
+loc = 'AAA'
+steps = 0
+while loc != 'ZZZ':
+	dir = next(insn)
+	loc = nodes[loc][move[dir]]
+	steps += 1
+
+print(f'it took {steps} steps to get from AAA to ZZZ.')

8/b.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+# Copyright 2023 Síle Ekaterin Liszka
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+from itertools import cycle
+from math import lcm
+
+insns = ''
+data = []
+
+with open('input.txt', mode='r') as f:
+	data = f.readlines()
+
+	insns = data[0][:-1]
+	data = data[2:]
+
+nodes = {}
+
+for line in data:
+	name, dest = line.split(' = ', maxsplit=1)
+	left, right = dest[1:-2].split(', ', maxsplit=1)
+	nodes[name] = (left, right)
+
+move = {'L': 0, 'R': 1}
+
+locs = [x for x in nodes.keys() if x.endswith('A')]
+steps = {}
+for loc in locs:
+	orig = loc
+	count = 0
+	insn = cycle(insns)
+	while not loc.endswith('Z'):
+		dir = next(insn)
+		loc = nodes[loc][move[dir]]
+		count += 1
+
+	steps[orig] = count
+
+steppy = steps.values()
+
+print(lcm(*steppy))