Day 11

[advent-of-code-2020.git] / day11 / seats.py

diff --git a/day11/seats.py b/day11/seats.py
new file mode 100755 (executable)
index 0000000..4a6bd92
--- /dev/null
+++ b/day11/seats.py
@@ -0,0 +1,160 @@
+#!/usr/bin/python3
+
+import sys
+import copy
+
+base_states=[]
+states=[]
+
+filename=(len(sys.argv) > 1) and sys.argv[1] or "37_26_seats.txt"
+
+base_states=[list(s.rstrip()) for s in open(filename, "r")]
+states=copy.deepcopy(base_states)
+
+def get_adjacent_seats(states, y, x, seat_map):
+    occupied=0
+    start_y=y-1
+    if y == 0:
+        start_y=0
+
+    end_y=y+1
+    if y >= len(states)-1:
+        end_y=y
+
+    start_x=x-1
+    if x == 0:
+        start_x=0
+
+    end_x=x+1
+    if x >= len(states[y])-1:
+        end_x=x
+
+    for check_y in range(start_y, end_y+1):
+        for check_x in range(start_x, end_x+1):
+            if check_y == y and check_x == x:
+                continue
+            if states[check_y][check_x] == "#":
+                occupied+=1
+
+    return occupied
+
+def get_nearest_seats(states, y, x, seat_map):
+    occupied=0
+    for seat in seat_map[y][x]:
+        if states[seat[0]][seat[1]] == "#":
+            occupied+=1
+
+    return occupied
+
+def calc_nearest_seats(states):
+    seats={}
+    for y,row in enumerate(states):
+        for x,seat in enumerate(row):
+            # only do anything if the seat is a seat
+            if seat == '.':
+                continue
+            daseats={}
+            for check_y,other_row in enumerate(states):
+                for check_x,other_seat in enumerate(other_row):
+                    # only do anything if the seat is a seat
+                    if other_seat == '.':
+                        continue
+                    # skip outselves
+                    if check_x == x and check_y == y:
+                        continue
+                    if abs(check_x - x) == abs(check_y - y):
+                        # this is one of the four diagonals
+                        if check_x > x and check_y > y:
+                            # down and right, getting further away
+                            # so if we've got a value ignore, other
+                            # wise add it
+                            if 'dr' not in daseats:
+                                daseats['dr']=[check_y,check_x]
+                        elif check_x > x and check_y < y:
+                            # up and right, getting closer
+                            daseats['ur']=[check_y,check_x]
+                        elif check_x < x and check_y < y:
+                            # up and left, getting closer, so always replace
+                            daseats['ul']=[check_y,check_x]
+                        elif check_x < x and check_y > y:
+                            # down and left getting further away
+                            if 'dl' not in daseats:
+                                daseats['dl']=[check_y,check_x]
+                    elif check_x > x and check_y == y:
+                        # heading right, getting further away
+                        # so if we've got a value ingore, other
+                        # wise add it
+                        if 'r' not in daseats:
+                            daseats['r']=[check_y,check_x]
+                    elif check_x < x and check_y == y:
+                        # heading left, getting closer
+                        daseats['l']=[check_y,check_x]
+                    elif check_y > y and check_x == x:
+                        # heading down, getting further away
+                        if 'd' not in daseats:
+                            daseats['d']=[check_y,check_x]
+                    elif check_y < y and check_x == x:
+                        # heading up
+                        daseats['u']=[check_y,check_x]
+            if not y in seats:
+                seats[y]={x: [seat for seat in daseats.values()]}
+            seats[y][x]=[seats for seats in daseats.values()]
+
+    return seats
+
+
+def apply_rules(states, check=get_adjacent_seats, max_people=4, seat_map=None):
+    new_states=copy.deepcopy(states)
+
+    for y in range(0, len(states)):
+        for x in range(0, len(states[0])):
+            if states[y][x] == ".":
+                continue
+            adj_seats=check(states, y, x, seat_map)
+            if states[y][x] == 'L' and adj_seats == 0:
+                new_states[y][x]='#'
+            elif states[y][x] == '#' and adj_seats >= max_people:
+                new_states[y][x]='L'
+
+    return new_states
+
+def get_seats(states):
+    return ''.join([''.join(s) for s in states])
+
+def print_layout(states, indent_string=""):
+    for line in states:
+        print(indent_string, ''.join(line))
+
+    print()
+
+previous_seats=get_seats(states)
+states=apply_rules(states)
+seats=get_seats(states)
+
+while seats!=previous_seats:
+    states=apply_rules(states)
+    previous_seats=seats
+    seats=get_seats(states)
+
+print("Part 1:")
+print("  Final state:")
+print_layout(states, "  ")
+print("  Occupied: {}".format(seats.count('#')))
+
+# now do part 2!
+states=copy.deepcopy(base_states)
+seat_map=calc_nearest_seats(states)
+
+previous_seats=get_seats(states)
+states=apply_rules(states,get_nearest_seats,5,seat_map)
+seats=get_seats(states)
+
+while seats!=previous_seats:
+    states=apply_rules(states,get_nearest_seats,5,seat_map)
+    previous_seats=seats
+    seats=get_seats(states)
+
+print("Part 2:")
+print("  Final state:")
+print_layout(states, "  ")
+print("  Occupied: {}".format(seats.count('#')))