Initial commit

1 files changed, 28 insertions, 0 deletions

diff --git a/2020/09/puzzle-1.py b/2020/09/puzzle-1.py
new file mode 100755
index 0000000..f68fc21
--- /dev/null
+++ b/2020/09/puzzle-1.py
@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+from typing import List
+
+
+def is_valid(nums: List[int], lp: int, up: int) -> bool:
+	for i in range(lp, up):
+		x = nums[up] - nums[i]
+		if x in nums[lp:up] and x != nums[i]:
+			return True
+	return False
+
+
+def main() -> None:
+	with open("input", "r") as f:
+		nums = list(map(int, f.readlines()))
+
+	lp = 0
+	up = 25
+
+	while is_valid(nums, lp, up):
+		lp += 1
+		up += 1
+
+	print(nums[up])
+
+
+if __name__ == "__main__":
+	main()