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- #!/usr/bin/python3
-
- """Solution for day 22 of Advent of Code 2016.
-
- Part 1 is straight-forward reading of the data, generating pairs using itertools.permutations, and counting how
- many match the criteria.
-
- As is traditional at about this point in Advent of Code, part 2 requires you to make annoying assumptions based on
- the vague example in the question and some properties of your input that you have no guarantee are universal.
-
- In this case, the input needs to be partitioned in to three sets: empty nodes (of which there is just one), giant
- nodes (whose data can't possibly be placed anywhere else) and normal nodes (who can shift their data to the empty
- node, but not to any other normal node).
-
- When the nodes are printed out according to their type (as in the example), it becomes obvious that there's a "wall"
- of giant nodes in the way. As the only valid moves involve the empty node, you basically have to move that around and
- use it to move the data along the top row.
-
- For my input, it takes 34 moves to rearrange things and then move the target data left by one:
-
- ..............23456789012345678901234
- ..............1......................
- ..............0######################
- ..............9876543................
- ....................2................
- ....................1................
- ...................._................
- .....................................
- .....................................
-
- Then for each node to the left it takes an additional five moves, as the empty space loops around our target:
-
- ....45_..
- ....321..
- .........
-
- It needs to move a total of 35 nodes left, so 34+35*5 total moves = 209.
- """
-
- import re
-
- import itertools
-
- matcher = re.compile(r'^/dev/grid/node-x([0-9]+)-y([0-9]+)\s+([0-9]+)T\s+([0-9]+)T\s+([0-9]+)T\s+.*$')
-
- # Constants used for convenient access the groups in the matcher above
- locx = 0
- locy = 1
- size = 2
- used = 3
- free = 4
-
- with open('data/22.txt', 'r') as data:
- discs = [tuple(map(int, matcher.match(l).groups())) for l in data.readlines() if matcher.match(l)]
- pairs = sum(1 for p in itertools.permutations(discs, 2) if 0 < p[0][used] <= p[1][free])
- print('Part one: %s' % pairs)
-
- print('Part two: ...')
- grid = dict((disc[:locy+1], disc) for disc in discs)
- for y in range(27):
- print(''.join(['X' if (x,y) not in grid
- else '_' if grid[(x, y)][used] == 0
- else '#' if grid[(x, y)][used] > 150 # Arbitrary cut-off for "normal" vs "giant" nodes
- else '.' for x in range(37)]))
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