122 lines
3.2 KiB
Python
122 lines
3.2 KiB
Python
from tools.aoc import AOCDay
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from typing import Any
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def getLegalMoves(positions):
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movers = [c for c in positions if positions[c]]
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for start in movers:
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finalPosition = True
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if start[1] == 0 or start[0] != positions[start] * 2:
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finalPosition = False
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else:
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for y in range(start[1] + 1, 5):
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if (start[0], y) in positions and positions[(start[0], y)] != positions[start]:
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finalPosition = False
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if finalPosition:
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continue
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if start[1] > 0 and positions[(start[0], start[1] - 1)]:
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continue
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possible_targets = []
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target_x = positions[start] * 2
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for y in [4, 3, 2, 1]:
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target = (target_x, y)
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if target not in positions:
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continue
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if positions[target] and positions[target] != positions[start]:
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break
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if positions[target] == positions[start]:
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continue
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if positions[(target_x, y - 1)]:
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continue
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possible_targets.append(target)
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break
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if start[1] != 0:
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for x in 0, 1, 3, 5, 7, 9, 10:
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if not positions[(x, 0)]:
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possible_targets.append((x, 0))
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for dest in possible_targets:
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if start == dest or positions[dest]:
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continue
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wayClear = True
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for x in range(min(start[0], dest[0]) + 1, max(start[0], dest[0])):
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if positions[(x, 0)]:
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wayClear = False
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break
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if not wayClear:
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continue
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yield start, dest, start[1] + abs(dest[0] - start[0]) + dest[1]
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def isFinalPosition(position):
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for x in 2, 4, 6, 8:
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for y in 1, 2, 3, 4:
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if (x, y) in position and position[(x, y)] != x // 2:
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return False
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return True
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def play(position, depth=0):
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if str(position) in DP:
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return DP[str(position)]
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minCost = 1e9
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for move in getLegalMoves(position):
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move_cost = 10 ** (position[move[0]] - 1) * move[2]
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new_pos = position.copy()
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new_pos[move[1]] = new_pos[move[0]]
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new_pos[move[0]] = 0
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if not isFinalPosition(new_pos):
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move_cost += play(new_pos, depth+1)
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if move_cost < minCost:
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minCost = move_cost
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DP[str(position)] = minCost
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return minCost
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DP = {}
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class Day(AOCDay):
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test_solutions_p1 = [12521, 12530]
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test_solutions_p2 = [44169, 50492]
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def getStartingPosition(self, part2=False):
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positions = {}
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for x in range(11):
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positions[(x, 0)] = 0
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my_input = self.getInput()[2:4]
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if part2:
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my_input = [my_input[0], " #D#C#B#A#", ' #D#B#A#C#', my_input[1]]
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for y, l in enumerate(my_input):
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for x, c in enumerate(l[2:].split("#")):
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if not c.strip():
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continue
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positions[(x * 2, y + 1)] = ord(c) - 64
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return positions
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def part1(self) -> Any:
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initPos = self.getStartingPosition()
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return play(initPos)
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def part2(self) -> Any:
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initPos = self.getStartingPosition(part2=True)
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return play(initPos)
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