2021 day2/python: add solution

2021/day2/day2.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+
+import sys
+
+if __name__ == '__main__':
+    x = 0
+    y = 0
+    z = 0
+    for line in sys.stdin.readlines():
+        dir, amount = line.split()
+        amount = int(amount)
+        if dir == 'forward':
+            x += amount
+            z += y * amount
+        elif dir == 'down':
+            y += amount
+        elif dir == 'up':
+            y -= amount
+    print(x*y)
+    print(x*z)