From 97e4d5284c810de7ae00f16f4752a414fa434799 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B8ren=20Rasmussen?= <sr@jondahl.net>
Date: Fri, 11 Dec 2020 10:16:16 +0100
Subject: [PATCH] Day 11 - Take two

---
 2020/11/main.py    | 80 +++++++++++++++++++++++++++++++++++++++++++---
 2020/11/test-2.txt |  9 ++++++
 2020/11/test-3.txt |  7 ++++
 2020/11/test-4.txt |  3 ++
 4 files changed, 95 insertions(+), 4 deletions(-)
 create mode 100644 2020/11/test-2.txt
 create mode 100644 2020/11/test-3.txt
 create mode 100644 2020/11/test-4.txt

diff --git a/2020/11/main.py b/2020/11/main.py
index b410cbb..7c632ba 100644
--- a/2020/11/main.py
+++ b/2020/11/main.py
@@ -29,6 +29,25 @@ class PuzzleSolver:
 
 		return n
 
+	def occupied_in_sight(self, ix, iy):
+		directions = [( 1, -1), ( 1,  0), ( 1,  1), ( 0,  1), (-1,  1), (-1,  0), (-1, -1), ( 0, -1)]
+		n = 0
+		for dx, dy in directions:
+			x, y = ix, iy
+			x += dx
+			y += dy
+			while 0 <= y < self.height and 0 <= x < self.width:
+				s = self.get(x, y)
+				if s == "#":
+					n += 1
+					break
+				if s == "L":
+					break
+				x += dx
+				y += dy
+
+		return n
+
 	def get(self, x, y):
 		return self.data[y][x]
 
@@ -50,11 +69,43 @@ class PuzzleSolver:
 
 		return ret
 
+	def mutate_in_sight(self):
+		ret = copy.deepcopy(self.data)
+		for y in range(self.height):
+			for x in range(self.width):
+				s = self.get(x, y)
+				if s == ".":
+					continue
+
+				n = self.occupied_in_sight(x, y)
+				if s == "L":
+					if n == 0:
+						ret[y][x] = "#"
+				elif s == "#":
+					if n >= 5:
+						ret[y][x] = "L"
+
+		return ret
+
 	def print(self):
 		for y in range(self.height):
 			print("".join(self.data[y]))
 		print()
 
+	def solve_in_sight(self):
+		stable = False
+		rounds = 0
+		self.print()
+		while not stable:
+			x = self.mutate_in_sight()
+			stable = x == self.data
+			self.data = x
+			rounds += 1
+
+			self.print()
+
+		return rounds
+
 	def solve(self):
 		stable = False
 		rounds = 0
@@ -73,12 +124,33 @@ class PuzzleSolver:
 		return sum([x.count("#") for x in self.data])
 
 
+#ps = PuzzleSolver("test.txt")
+#rounds = ps.solve()
+#cs = PuzzleSolver("test-1.txt")
+#assert ps.data == cs.data
+#
+#ps = PuzzleSolver("data.txt")
+#rounds = ps.solve()
+#n = ps.count_occupied()
+#print(f"There are {n} occupied seats.")
+
+ps = PuzzleSolver("test-2.txt")
+assert ps.get(3, 4) == "L"
+assert ps.occupied_in_sight(3, 4) == 8
+
+ps = PuzzleSolver("test-3.txt")
+assert ps.get(3, 3) == "L"
+assert ps.occupied_in_sight(3, 3) == 0
+
+ps = PuzzleSolver("test-4.txt")
+assert ps.get(1, 1) == "L"
+assert ps.occupied_in_sight(1, 1) == 0
+
 ps = PuzzleSolver("test.txt")
-rounds = ps.solve()
-cs = PuzzleSolver("test-1.txt")
-assert ps.data == cs.data
+ps.solve_in_sight()
+assert ps.count_occupied() == 26
 
 ps = PuzzleSolver("data.txt")
-rounds = ps.solve()
+ps.solve_in_sight()
 n = ps.count_occupied()
 print(f"There are {n} occupied seats.")
diff --git a/2020/11/test-2.txt b/2020/11/test-2.txt
new file mode 100644
index 0000000..a486e35
--- /dev/null
+++ b/2020/11/test-2.txt
@@ -0,0 +1,9 @@
+.......#.
+...#.....
+.#.......
+.........
+..#L....#
+....#....
+.........
+#........
+...#.....
diff --git a/2020/11/test-3.txt b/2020/11/test-3.txt
new file mode 100644
index 0000000..68e6543
--- /dev/null
+++ b/2020/11/test-3.txt
@@ -0,0 +1,7 @@
+.##.##.
+#.#.#.#
+##...##
+...L...
+##...##
+#.#.#.#
+.##.##.
diff --git a/2020/11/test-4.txt b/2020/11/test-4.txt
new file mode 100644
index 0000000..bb0b813
--- /dev/null
+++ b/2020/11/test-4.txt
@@ -0,0 +1,3 @@
+.............
+.L.L.#.#.#.#.
+.............