From 26ba2304d9246de3beb3ab8c3a807b7457e20796 Mon Sep 17 00:00:00 2001
From: augustin64 <me.git@augustin64.fr>
Date: Fri, 8 Dec 2023 10:47:09 +0100
Subject: [PATCH] Add 2023 day 08

---
 2023/day08.py | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100755 2023/day08.py

diff --git a/2023/day08.py b/2023/day08.py
new file mode 100755
index 0000000..24d6e09
--- /dev/null
+++ b/2023/day08.py
@@ -0,0 +1,67 @@
+#!/usr/bin/python3
+"""
+Jour 08 du défi Advent Of Code pour l'année 2023
+"""
+
+def gcd(a, b):
+    while b:
+        a, b = b, a % b
+    return a
+
+def lcm(a, b):
+    return (a * b) // gcd(a, b)
+
+def lcm_of_list(numbers):
+    result = 1
+    for num in numbers:
+        result = lcm(result, num)
+    return result
+
+
+
+def read_sample():
+    """récupère les entrées depuis le fichier texte correspondant"""
+    with open('inputs/day08.txt', 'r') as f:
+        sample = f.read().split('\n')
+    sample = [ i for i in sample if i != '' ]
+    return sample
+
+def parse_sample(sample):
+    instructions = sample[0]
+    mappings = {
+        i.split(" = ")[0]: (i.split(" = ")[1].split(", ")[0].replace("(", ""), i.split(" = ")[1].split(", ")[1].replace(")", ""))
+        for i in (sample[1:]) if i != ""
+    }
+    return instructions, mappings
+
+def number_steps(instructions, mappings, pos, untilZZZ=True):
+    step = 0
+    instr = {
+        "R": 1, "L": 0
+    }
+    while (pos[-1] != 'Z') or (untilZZZ and pos != "ZZZ"):
+        pos = mappings[pos][instr[instructions[step%len(instructions)]]]
+        step += 1
+    return step
+
+def part1(sample):
+    """Partie 1 du défi"""
+    instructions, mappings = parse_sample(sample)
+    return number_steps(instructions, mappings, "AAA")
+
+def part2(sample):
+    """Partie 2 du défi"""
+    instructions, mappings = parse_sample(sample)
+    a_ending = [i for i in mappings.keys() if i[-1] == 'A']
+    steps = [number_steps(instructions, mappings, i, untilZZZ=False) for i in a_ending]
+    return lcm_of_list(steps)
+
+
+def main():
+    """Fonction principale"""
+    sample = read_sample()
+    print(f"part1: {part1(sample)}")
+    print(f"part2: {part2(sample)}")
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file