Add code for 2015 advent that I did historically.

day_3/part_2.py

@@ -0,0 +1,54 @@
+# with open("input", "r") as data:
+data = input()
+
+unique_houses = 1
+santa_coord = [0, 0]
+robo_coord = [0, 0]
+historic_coords = [f"0,0"]
+is_real_santa = True
+
+
+
+# Get each instruction
+for direction in data:
+
+	# Heading north
+	if direction == "^":
+		if is_real_santa: santa_coord[1] += 1
+		else: robo_coord[1] += 1
+
+	# Heading south
+	elif direction == "v":
+		if is_real_santa: santa_coord[1] -= 1
+		else: robo_coord[1] -= 1
+
+	# Heading west
+	elif direction == "<":
+		if is_real_santa: santa_coord[0] -= 1
+		else: robo_coord[0] -= 1
+
+	# Heading east
+	elif direction == ">":
+		if is_real_santa: santa_coord[0] += 1
+		else: robo_coord[0] += 1
+
+	# Unknown input
+	else: raise Exception(f"InputError: Unexpected input: {direction}")
+
+
+	# Get coordinate string
+	if is_real_santa: coord_string = f"{santa_coord[0]},{santa_coord[1]}"
+	else: f"{robo_coord[0]},{robo_coord[1]}"
+
+
+	# Check if we've been here already
+	if not (coord_string in historic_coords):
+
+		# New house, keep track of it
+		unique_houses += 1
+		historic_coords += [coord_string]
+
+	is_real_santa = not is_real_santa
+
+
+print(f"Total Houses With At Least One Present: {unique_houses}")