Added solutions for day 11

askrepps · askrepps · commit 0266c0dfd2d1 · 2020-12-11T21:55:25.000-05:00
diff --git a/advent2020/day11.py b/advent2020/day11.py
@@ -0,0 +1,87 @@
+# MIT License
+#
+# Copyright (c) 2020 Andrew Krepps
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+from . import util
+
+
+def search_filled_seat(grid, row, col, row_dir, col_dir, search_lim):
+    distance = 0
+    while True:
+        distance += 1
+        if search_lim is not None and distance > search_lim:
+            return False
+        search_row = row + row_dir*distance
+        search_col = col + col_dir*distance
+        if search_row not in range(len(grid)) or search_col not in range(len(grid[0])):
+            return False
+        if grid[search_row][search_col] == '#':
+            return True
+        if grid[search_row][search_col] == 'L':
+            return False
+
+
+def count_adjacent_filled_seats(grid, row, col, search_lim):
+    count = 0
+    for row_dir in range(-1, 2):
+        for col_dir in range(-1, 2):
+            if (row_dir, col_dir) != (0, 0) and search_filled_seat(grid, row, col, row_dir, col_dir, search_lim):
+                count += 1
+    return count
+
+
+def run_seat_simulation(seat_grid, search_lim, vacate_threshold):
+    grid1 = [[cell for cell in row] for row in seat_grid]
+    grid2 = [['X' for col in row] for row in grid1]
+    while grid1 != grid2:
+        for row in range(len(grid1)):
+            for col in range(len(grid1[0])):
+                adjacent_count = count_adjacent_filled_seats(grid1, row, col, search_lim)
+                if grid1[row][col] == 'L' and adjacent_count == 0:
+                    grid2[row][col] = '#'
+                elif grid1[row][col] == '#' and adjacent_count >= vacate_threshold:
+                    grid2[row][col] = 'L'
+                else:
+                    grid2[row][col] = grid1[row][col]
+        grid1, grid2 = grid2, grid1
+    return grid1
+
+
+def count_filled_seats(seat_grid):
+    return sum([sum([1 for col in row if col == '#']) for row in seat_grid])
+
+
+def get_part1_answer(seat_grid):
+    stable_grid = run_seat_simulation(seat_grid, search_lim=1, vacate_threshold=4)
+    return count_filled_seats(stable_grid)
+
+
+def get_part2_answer(seat_grid):
+    stable_grid = run_seat_simulation(seat_grid, search_lim=None, vacate_threshold=5)
+    return count_filled_seats(stable_grid)
+
+
+def run():
+    with open(util.get_input_file_path("day11.txt")) as f:
+        seat_grid = [line.strip() for line in f if len(line.strip()) > 0]
+        print(f"The answer to part 1 is {get_part1_answer(seat_grid)}")
+        print(f"The answer to part 2 is {get_part2_answer(seat_grid)}")
diff --git a/main.py b/main.py
@@ -33,6 +33,7 @@
 from advent2020 import day8
 from advent2020 import day9
 from advent2020 import day10
+from advent2020 import day11
 
 
 day_runners = [
@@ -45,7 +46,8 @@
     lambda: day7.run(),
     lambda: day8.run(),
     lambda: day9.run(),
-    lambda: day10.run()
+    lambda: day10.run(),
+    lambda: day11.run()
 ]
 
 
diff --git a/test/test_day11.py b/test/test_day11.py
@@ -0,0 +1,48 @@
+# MIT License
+#
+# Copyright (c) 2020 Andrew Krepps
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+
+import unittest
+
+from advent2020.day11 import get_part1_answer
+from advent2020.day11 import get_part2_answer
+
+
+seat_data = """
+L.LL.LL.LL
+LLLLLLL.LL
+L.L.L..L..
+LLLL.LL.LL
+L.LL.LL.LL
+L.LLLLL.LL
+..L.L.....
+LLLLLLLLLL
+L.LLLLLL.L
+L.LLLLL.LL
+"""
+
+
+class Day11Test(unittest.TestCase):
+    def test_day11(self):
+        seat_grid = [line.strip() for line in seat_data.split("\n") if len(line.strip()) > 0]
+        self.assertEqual(get_part1_answer(seat_grid), 37)
+        self.assertEqual(get_part2_answer(seat_grid), 26)
