2016: d05: ex2: add solution

2016/d05/ex2/ex2.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python
+
+import hashlib
+import itertools
+import sys
+
+
+def solve(input: str) -> str:
+    def crack_password(door_id: str) -> str:
+        password = ["_"] * 8
+        for i in itertools.count():
+            hash = hashlib.md5((door_id + str(i)).encode()).hexdigest()
+            if not hash.startswith("00000"):
+                continue
+            pos = hash[5]
+            if pos not in ("0", "1", "2", "3", "4", "5", "6", "7"):
+                continue
+            if password[int(pos)] != "_":
+                continue
+            password[int(pos)] = hash[6]
+            if all(c != "_" for c in password):
+                break
+        return "".join(password)
+
+    return crack_password(input.strip())
+
+
+def main() -> None:
+    input = sys.stdin.read()
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()