2020: d10: ex1: add solution

2020/d10/ex1/ex1.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+import sys
+from collections import defaultdict
+from typing import Dict, List
+
+
+def make_chain(adapters: List[int]) -> int:
+    adapters = sorted(adapters)
+    output = 0
+    device = adapters[-1] + 3
+    jolts: Dict[int, int] = defaultdict(int)
+    for adapter in adapters:
+        delt = adapter - output
+        jolts[delt] += 1
+        output = adapter
+    jolts[device - output] += 1
+
+    return jolts[1] * jolts[3]
+
+
+def solve(raw: List[str]) -> int:
+    return make_chain([int(line) for line in raw])
+
+
+def main() -> None:
+    input = [line.strip() for line in sys.stdin.readlines()]
+    print(solve(input))
+
+
+if __name__ == "__main__":
+    main()