Solve 2018/06

2018/06/solve.py

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+import sys
+
+# PART 1
+
+def load_coords(filename):
+	coords = []
+	with open(filename, "r") as f:
+		for line in f:
+			x, y = line[:-1].split(", ")
+			x, y = int(x), int(y)
+			coords.append((x, y))
+	return coords
+
+class Voronoi:
+	def __init__(self, min_x, min_y, max_x, max_y):
+		self.min_x = min_x
+		self.min_y = min_y
+		self.max_x = max_x
+		self.max_y = max_y
+
+		self.cells = {}
+
+	def add(self, pos_x, pos_y):
+		for x in range(self.min_x, self.max_x + 1):
+			for y in range(self.min_y, self.max_y + 1):
+				self.add_to_cell(pos_x, pos_y, x, y)
+		print(f"Added ({pos_x}, {pos_y})")
+
+	def add_to_cell(self, pos_x, pos_y, cell_x, cell_y):
+		pos = (pos_x, pos_y)
+		cell = (cell_x, cell_y)
+		dist = abs(pos_x - cell_x) + abs(pos_y - cell_y)
+
+		if cell in self.cells:
+			cdist, cpos = self.cells[cell]
+			if dist < cdist:
+				self.cells[cell] = (dist, pos)
+			elif dist == cdist and cpos is not None:
+				self.cells[cell] = (dist, None)
+			# else: pass
+		else:
+			self.cells[cell] = (dist, pos)
+
+	@classmethod
+	def from_coords(cls, coords):
+		xs = [x for x, _ in coords]
+		ys = [y for _, y in coords]
+
+		voro = cls(min(xs), min(ys), max(xs), max(ys))
+		for x, y in coords:
+			voro.add(x, y)
+
+		return voro
+
+	def find_ignore(self):
+		ignore = set()
+		for x in range(self.min_x, self.max_x + 1):
+			_, pos1 = self.cells.get((x, self.min_y))
+			_, pos2 = self.cells.get((x, self.max_y))
+			ignore.add(pos1)
+			ignore.add(pos2)
+		for y in range(self.min_y, self.max_y + 1):
+			_, pos1 = self.cells.get((self.min_x, y))
+			_, pos2 = self.cells.get((self.max_x, y))
+			ignore.add(pos1)
+			ignore.add(pos2)
+		return ignore
+
+	def find_largest(self):
+		ignore = self.find_ignore()
+
+		count = {}
+		for x in range(self.min_x + 1, self.max_x):
+			for y in range(self.min_y + 1, self.max_y):
+				_, pos = self.cells.get((x, y))
+				if pos not in ignore:
+					count[pos] = count.get(pos, 0) + 1
+
+		return max(count.values())
+
+# PART 2
+
+class Nearest:
+	def __init__(self, coords):
+		self.coords = coords
+
+		xs = [x for x, _ in self.coords]
+		ys = [y for _, y in self.coords]
+
+		self.min_x = min(xs)
+		self.min_y = min(ys)
+		self.max_x = max(xs)
+		self.max_y = max(ys)
+
+	def find(self):
+		cells = set()
+
+		for x in range(self.min_x, self.max_x + 1):
+			for y in range(self.min_y, self.max_y + 1):
+				if self.evaluate(x, y):
+					cells.add((x, y))
+
+		return len(cells)
+
+	def evaluate(self, pos_x, pos_y):
+		pos = (pos_x, pos_y)
+		dist = 0
+		for x, y in self.coords:
+			dist += abs(pos_x - x) + abs(pos_y - y)
+		return dist < 10000
+
+def main(filename):
+	print(f"Solutions for {filename}")
+	coords = load_coords(filename)
+	voro = Voronoi.from_coords(coords)
+	largest = voro.find_largest()
+	print(f"Part 1: {largest}")
+	nearest = Nearest(coords)
+	largest_2 = nearest.find()
+	print(f"Part 2: {largest_2}")
+
+if __name__ == "__main__":
+	for filename in sys.argv[1:]:
+		main(filename)