day23

day23.py

@@ -1,19 +1,15 @@
 from tools.aoc import AOCDay
 from typing import Any
-import sys
-sys.setrecursionlimit(2000)
 
 
 def getLegalMoves(positions):
     movers = [c for c in positions if positions[c]]
-    moves = []
 
     for start in movers:
         finalPosition = True
         if start[1] == 0 or start[0] != positions[start] * 2:
             finalPosition = False
         else:
-            if start[1] > 0 and start[0] == positions[start] * 2:
             for y in range(start[1] + 1, 5):
                 if (start[0], y) in positions and positions[(start[0], y)] != positions[start]:
                     finalPosition = False
@@ -31,6 +27,9 @@ def getLegalMoves(positions):
             if target not in positions:
                 continue
 
+            if positions[target] and positions[target] != positions[start]:
+                break
+
             if positions[target] == positions[start]:
                 continue
 
@@ -57,103 +56,66 @@ def getLegalMoves(positions):
             if not wayClear:
                 continue
 
-            #yield start, dest, start[1] + abs(dest[0] - start[0]) + dest[1]
-            moves.append((start, dest, start[1] + abs(dest[0] - start[0]) + dest[1]))
-
-    return moves
+            yield start, dest, start[1] + abs(dest[0] - start[0]) + dest[1]
 
 
-gMinCost = 1e5
-DP = {}
-
-
-def isFinalPosition(position, cost):
-    global gMinCost
+def isFinalPosition(position):
     for x in 2, 4, 6, 8:
         for y in 1, 2, 3, 4:
             if (x, y) in position and position[(x, y)] != x // 2:
                 return False
 
-    if gMinCost > cost:
-        print("Found final position with cost", cost)
-        gMinCost = cost
-
     return True
 
 
-def play(position, cost):
-    if (str(position), cost) in DP:
-        return DP[str(position), cost]
+def play(position, depth=0):
+    if str(position) in DP:
+        return DP[str(position)]
 
-    minCost = 5e4
+    minCost = 1e9
     for move in getLegalMoves(position):
-        move_cost = cost + 10 ** (position[move[0]] - 1) * move[2]
-        this_cost = move_cost
-        if this_cost > gMinCost:
-            continue
+        move_cost = 10 ** (position[move[0]] - 1) * move[2]
         new_pos = position.copy()
         new_pos[move[1]] = new_pos[move[0]]
         new_pos[move[0]] = 0
-        if not isFinalPosition(new_pos, this_cost):
-            this_cost += play(new_pos, this_cost)
-        if this_cost < minCost:
-            minCost = this_cost
+        if not isFinalPosition(new_pos):
+            move_cost += play(new_pos, depth+1)
+        if move_cost < minCost:
+            minCost = move_cost
 
-    DP[str(position), cost] = minCost
+    DP[str(position)] = minCost
     return minCost
 
 
+DP = {}
+
+
 class Day(AOCDay):
-    test_solutions_p1 = [12521]
-    test_solutions_p2 = [44169]
+    test_solutions_p1 = [12521, 12530]
+    test_solutions_p2 = [44169, 50492]
 
     def getStartingPosition(self, part2=False):
         positions = {}
         for x in range(11):
             positions[(x, 0)] = 0
 
-        y1 = self.getInput()[2].split("#")
-        positions[(2, 1)] = ord(y1[3]) - 64
-        positions[(4, 1)] = ord(y1[4]) - 64
-        positions[(6, 1)] = ord(y1[5]) - 64
-        positions[(8, 1)] = ord(y1[6]) - 64
-        if not part2:
-            y2 = self.getInput()[3].split("#")
-            positions[(2, 2)] = ord(y2[1]) - 64
-            positions[(4, 2)] = ord(y2[2]) - 64
-            positions[(6, 2)] = ord(y2[3]) - 64
-            positions[(8, 2)] = ord(y2[4]) - 64
-        else:
-            my1 = "#D#C#B#A#".split("#")
-            positions[(2, 2)] = ord(my1[1]) - 64
-            positions[(4, 2)] = ord(my1[2]) - 64
-            positions[(6, 2)] = ord(my1[3]) - 64
-            positions[(8, 2)] = ord(my1[4]) - 64
-            my2 = "#D#B#A#C#".split("#")
-            positions[(2, 3)] = ord(my2[1]) - 64
-            positions[(4, 3)] = ord(my2[2]) - 64
-            positions[(6, 3)] = ord(my2[3]) - 64
-            positions[(8, 3)] = ord(my2[4]) - 64
-            y2 = self.getInput()[3].split("#")
-            positions[(2, 4)] = ord(y2[1]) - 64
-            positions[(4, 4)] = ord(y2[2]) - 64
-            positions[(6, 4)] = ord(y2[3]) - 64
-            positions[(8, 4)] = ord(y2[4]) - 64
+        my_input = self.getInput()[2:4]
+        if part2:
+            my_input = [my_input[0], "  #D#C#B#A#", '  #D#B#A#C#', my_input[1]]
+
+        for y, l in enumerate(my_input):
+            for x, c in enumerate(l[2:].split("#")):
+                if not c.strip():
+                    continue
+
+                positions[(x * 2, y + 1)] = ord(c) - 64
 
         return positions
 
     def part1(self) -> Any:
-        global gMinCost
-        gMinCost = 5e4
         initPos = self.getStartingPosition()
-        print(play(initPos, 0))
-        return gMinCost
+        return play(initPos)
 
     def part2(self) -> Any:
-        global gMinCost
-        gMinCost = 5e4
         initPos = self.getStartingPosition(part2=True)
-        print(initPos)
-        print(len(list(getLegalMoves(initPos))), list(getLegalMoves(initPos)))
-        play(initPos, 0)
-        return gMinCost
+        return play(initPos)

inputs/test_input23_1_1

@@ -0,0 +1,5 @@
+#############
+#...........#
+###C#D#D#A###
+  #B#A#B#C#
+  #########

inputs/test_input23_2_1

@@ -0,0 +1,5 @@
+#############
+#...........#
+###C#D#D#A###
+  #B#A#B#C#
+  #########