Move python solutions to separate directory

py/2015/03/solve.py

@@ -0,0 +1,47 @@
+import sys
+
+def load_steps(filename):
+	with open(filename, "r") as f:
+		return f.read()[:-1]
+
+# PART 1
+
+def find_doubles(steps):
+	x, y = 0, 0
+	houses = {(0, 0)}
+	for step in steps:
+		if   step == "^": y += 1
+		elif step == "v": y -= 1
+		elif step == "<": x -= 1
+		elif step == ">": x += 1
+		houses.add((x, y))
+	return houses
+
+# PART 2
+
+def split_string(s):
+	s1 = ""
+	s2 = ""
+	while True:
+		if not s: break
+		s1 += s[0]
+		s = s[1:]
+		if not s: break
+		s2 += s[0]
+		s = s[1:]
+	return s1, s2
+
+def main(filename):
+	steps = load_steps(filename)
+	print(f"Solutions for {filename}")
+	doubles = len(find_doubles(steps))
+	print(f"Part 1: {doubles}")
+	santa, robot = split_string(steps)
+	santa_doubles = find_doubles(santa)
+	robot_doubles = find_doubles(robot)
+	doubles_2 = len(santa_doubles | robot_doubles)
+	print(f"Part 2: {doubles_2}")
+
+if __name__ == "__main__":
+	for filename in sys.argv[1:]:
+		main(filename)