add day 8

.gitignore

@@ -1,2 +1,2 @@
-*input
+*input*
 

7/7.py

@@ -143,7 +143,7 @@ def main(input_file: typer.FileText):
         )
 
     print(f"Part 1 total winnings: {total_winnings}")
-    
+
     hands = []
     global card_values
     global card_values_joker
@@ -170,6 +170,5 @@ def main(input_file: typer.FileText):
     print(f"Part 2 total winnings: {total_winnings}")
 
 
-
 if __name__ == "__main__":
     typer.run(main)

8/8.py

@@ -0,0 +1,68 @@
+import typer
+import math
+
+
+def part1(nodes, instructions):
+    current_node = "AAA"
+    instructions_traversed = 0
+    if "AAA" not in nodes:
+        return
+    while True:
+        for instruction in instructions:
+            current_node = nodes[current_node][instruction]
+            instructions_traversed += 1
+            if current_node == "ZZZ":
+                break
+        if current_node == "ZZZ":
+            break
+
+    print(f"Part 1: instructions traversed: {instructions_traversed}")
+
+
+def part2(nodes, instructions):
+    current_nodes = [node for node in nodes if node.endswith("A")]
+    periods = []
+    for current_node in current_nodes:
+        instructions_traversed = 0
+        period = None
+        while True:
+            for instruction in instructions:
+                current_node = nodes[current_node][instruction]
+                instructions_traversed += 1
+                if current_node.endswith("Z"):
+                    periods.append(instructions_traversed)
+                    break
+            if current_node.endswith("Z"):
+                break
+
+    gcd = math.gcd(*periods)
+    periods = [p // gcd for p in periods]
+    product = math.prod(periods)
+    instructions_traversed = product * gcd
+    print(f"Part2: {instructions_traversed}")
+
+
+def main(input_file: typer.FileText):
+    input = input_file.read().split("\n")
+
+    nodes = {}
+    instructions = ""
+    for row in input:
+        if row == "":
+            continue
+        elif "=" in row:
+            values = row.split("=")
+            name = values[0].strip()
+            directions = values[1].strip("(), ").split(", ")
+            left = directions[0]
+            right = directions[1]
+            nodes[name] = {"L": directions[0], "R": directions[1]}
+        else:
+            instructions = row.strip()
+
+    part1(nodes, instructions)
+    part2(nodes, instructions)
+
+
+if __name__ == "__main__":
+    typer.run(main)