Solve 2016/01

2016/01/input.txt

@@ -0,0 +1 @@
+L4, R2, R4, L5, L3, L1, R4, R5, R1, R3, L3, L2, L2, R5, R1, L1, L2, R2, R2, L5, R5, R5, L2, R1, R2, L2, L4, L1, R5, R2, R1, R1, L2, L3, R2, L5, L186, L5, L3, R3, L5, R4, R2, L5, R1, R4, L1, L3, R3, R1, L1, R4, R2, L1, L4, R5, L1, R50, L4, R3, R78, R4, R2, L4, R3, L4, R4, L1, R5, L4, R1, L2, R3, L2, R5, R5, L4, L1, L2, R185, L5, R2, R1, L3, R4, L5, R2, R4, L3, R4, L2, L5, R1, R2, L2, L1, L2, R2, L2, R1, L5, L3, L4, L3, L4, L2, L5, L5, R2, L3, L4, R4, R4, R5, L4, L2, R4, L5, R3, R1, L1, R3, L2, R2, R1, R5, L4, R5, L3, R2, R3, R1, R4, L4, R1, R3, L5, L1, L3, R2, R1, R4, L4, R3, L3, R3, R2, L3, L3, R4, L2, R4, L3, L4, R5, R1, L1, R5, R3, R1, R3, R4, L1, R4, R3, R1, L5, L5, L4, R4, R3, L2, R1, R5, L3, R4, R5, L4, L5, R2

2016/01/solve.py

@@ -0,0 +1,74 @@
+import sys
+
+def load_steps(filename):
+	steps = []
+	with open(filename, "r") as f:
+		for step in f.read()[:-1].split(","):
+			step = step.strip()
+			step = (step[0], int(step[1:]))
+			steps.append(step)
+	return steps
+
+# PART 1
+
+def turn(direction, where):
+	dir_x, dir_y = direction
+
+	if where == "R":
+		return (dir_y, -dir_x)
+	elif where == "L":
+		return (-dir_y, dir_x)
+	else:
+		raise Exception("HEY! Don't do that!")
+
+def manhattan(position):
+	x, y = position
+	return abs(x) + abs(y)
+
+def find_distance(steps):
+	pos_x, pos_y = 0, 0
+	direction = (1, 0)
+
+	for step in steps:
+		where, amount = step
+		direction = turn(direction, where)
+		dir_x, dir_y = direction
+		pos_x += dir_x * amount
+		pos_y += dir_y * amount
+
+	return manhattan((pos_x, pos_y))
+
+# PART 2
+
+def first_visited_twice(steps):
+	pos_x, pos_y = 0, 0
+	direction = (1, 0)
+	visited = {(pos_x, pos_y)}
+
+	for step in steps:
+		where, amount = step
+		direction = turn(direction, where)
+		dir_x, dir_y = direction
+
+		for i in range(amount):
+			pos_x += dir_x
+			pos_y += dir_y
+			position = (pos_x, pos_y)
+
+			if position in visited:
+				return position
+			else:
+				visited.add(position)
+
+def main(filename):
+	steps = load_steps(filename)
+	print(f"Solutions for {filename}")
+	distance = find_distance(steps)
+	print(f"Part 1: {distance}")
+	pos = first_visited_twice(steps)
+	distance_2 = manhattan(pos)
+	print(f"Part 2: {distance_2}")
+
+if __name__ == "__main__":
+	for filename in sys.argv[1:]:
+		main(filename)