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103 lines
2.2 KiB
Python
103 lines
2.2 KiB
Python
"""Solution to 2020/23"""
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from collections import deque
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EXAMPLE = '389125467'
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INPUT = '952316487'
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# INPUT = EXAMPLE
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MOVES = 10_000_000
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INPUT = list(map(int, INPUT))
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INPUT = INPUT + list(range(max(INPUT) + 1, 1_000_000 + 1))
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def main():
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cups = CrabCups(INPUT)
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print(cups)
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for move in range(MOVES):
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if move % 1_000_000 == 0:
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print(f'-- MOVE {move} --')
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cups.move()
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print()
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print('finished')
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print(cups._nodes[1].next.value * cups._nodes[1].next.next.value)
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exit()
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class CrabCups:
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def __init__(self, cups):
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nodes = dict()
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i = 0
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prev = None
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while i < len(cups):
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node = Node(cups[i])
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if prev:
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node.prev = prev
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prev.next = node
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prev = node
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nodes[cups[i]] = node
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i += 1
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nodes[cups[0]].prev = nodes[cups[-1]]
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nodes[cups[-1]].next = nodes[cups[0]]
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self._nodes = nodes
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self.cur = nodes[cups[0]]
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self.cup_count = len(cups)
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self.last_cur = None
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self.last_pick_up = None
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self.last_destination = None
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def move(self):
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pick_up = set()
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link = self.cur
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self.last_cur = self.cur
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self.last_pick_up = link.next
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for _ in range(3):
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link = link.next
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pick_up.add(link.value)
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# wire cur with cup after pickups
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link.next.prev = self.cur
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self.cur.next = link.next
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# find dest
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dest = self.cur.value - 1
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dest = dest if dest != 0 else self.cup_count
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while dest in pick_up:
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dest -= 1
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dest = dest if dest != 0 else self.cup_count
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dest = self._nodes[dest]
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self.last_dest = dest
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dest.next.prev = link
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link.next = dest.next
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link = link.prev.prev
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dest.next = link
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link.prev = dest
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self.cur = self.cur.next
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def as_list(self, start):
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cups = [start.value]
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cur = start.next
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while not cur is start:
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cups.append(cur.value)
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cur = cur.next
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return cups
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class Node:
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next = None
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prev = None
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def __init__(self, val):
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self.value = val
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main()
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