From 9128f6bdc40d204325a30cff86429356ef2fc5da Mon Sep 17 00:00:00 2001
From: Dan Buch <dan@meatballhat.com>
Date: Sun, 3 Jan 2021 20:03:45 -0500
Subject: [PATCH] A terrible idea oh no

---
 aoc2020/day02/solution.py | 50 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 aoc2020/day02/solution.py

diff --git a/aoc2020/day02/solution.py b/aoc2020/day02/solution.py
new file mode 100644
index 0000000..69a2193
--- /dev/null
+++ b/aoc2020/day02/solution.py
@@ -0,0 +1,50 @@
+import sys
+
+
+def main() -> int:
+    n_valid = 0
+    total = 0
+
+    for pol_pas in [PolicyPassword.fromstring(s) for s in sys.stdin.readlines(False)]:
+        if pol_pas.is_valid():
+            n_valid += 1
+        total += 1
+
+    print(f"{n_valid}/{total} valid")
+
+    return 0
+
+
+class Policy:
+    def __init__(self, char: str, min_count: int, max_count: int):
+        self.char = char
+        self.min_count = min_count
+        self.max_count = max_count
+
+    @classmethod
+    def fromstring(cls, input_string) -> "Policy":
+        parts = [s.strip() for s in input_string.split(" ")][:2]
+        min_max = [int(s) for s in parts[0].split("-")][:2]
+        return cls(parts[1], min_max[0], min_max[1])
+
+    def is_valid(self, password: str) -> bool:
+        actual = password.count(self.char)
+        return actual >= self.min_count and actual <= self.max_count
+
+
+class PolicyPassword:
+    def __init__(self, policy: "Policy", password: str):
+        self.policy = policy
+        self.password = password
+
+    @classmethod
+    def fromstring(cls, input_string: str) -> "PolicyPassword":
+        parts = [s.strip() for s in input_string.split(":")][:2]
+        return cls(Policy.fromstring(parts[0]), parts[1])
+
+    def is_valid(self) -> bool:
+        return self.policy.is_valid(self.password)
+
+
+if __name__ == "__main__":
+    sys.exit(main())