solve Day08 in Python

Day08/python/solution2.py

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+import sys
+from math import gcd
+
+def parse_file(file_path):
+    print(f"Parsing file: {file_path}")
+    with open(file_path, 'r') as file:
+        D = file.read().strip()
+    steps, rule = D.split('\n\n')
+    GO = {'L': {}, 'R': {}}
+    for line in rule.split('\n'):
+        st, lr = line.split('=')
+        left, right = lr.split(',')
+        GO['L'][st.strip()] = left.strip()[1:].strip()
+        GO['R'][st.strip()] = right[:-1].strip()
+    return [0 if char == 'L' else 1 for char in steps], GO
+
+def lcm(xs):
+    ans = 1
+    for x in xs:
+        ans = (x * ans) // gcd(x, ans)
+    return ans
+
+def navigate_network_simultaneously(steps, GO):
+    print("Starting navigation of network.")
+    POS = [s for s in GO['L'] if s.endswith('A')]
+    T = {}
+    t = 0
+    while True:
+        NP = []
+        for i, p in enumerate(POS):
+            p = GO['L' if steps[t % len(steps)] == 0 else 'R'][p]
+            if p.endswith('Z'):
+                T[i] = t + 1
+                if len(T) == len(POS):
+                    print(f"All paths reached 'Z' nodes at step {t + 1}.")
+                    return lcm(T.values())
+            NP.append(p)
+        POS = NP
+        t += 1
+        print(f"Step {t}: Current nodes - {POS}")
+    assert False
+
+def run_test():
+    print("Running test...")
+    expected_result = 6
+    steps, GO = parse_file("../test2.txt")
+    result = navigate_network_simultaneously(steps, GO)
+    assert result == expected_result, f"Test failed, expected {expected_result} but got {result}"
+    print(f"Test passed with {result} steps.")
+
+def main():
+    run_test()
+    steps, GO = parse_file("../input.txt")
+    result = navigate_network_simultaneously(steps, GO)
+    print(f"All paths reached 'Z' nodes simultaneously in {result} steps.")
+
+if __name__ == "__main__":
+    main()