Created
December 10, 2017 06:24
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Advent of Code 2017, Day 10
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| INPUT = """165,1,255,31,87,52,24,113,0,91,148,254,158,2,73,153""" | |
| import asciitree | |
| from collections import OrderedDict, defaultdict | |
| def _replace(data, position, chunk): | |
| #print position, chunk | |
| for idx, v in enumerate(chunk): | |
| data[position+idx] = v | |
| def hash_list(lengths, data, position=0, skip_size=0): | |
| #print position, skip_size, data | |
| base_len = len(data) | |
| for length in lengths: | |
| #print length | |
| data = data | |
| end = position+length | |
| if end >= base_len: | |
| data = data + data | |
| chunk = data[position:end] | |
| #print position, end, chunk, '->', | |
| chunk.reverse() | |
| #print chunk | |
| if end >= base_len: | |
| data = data[:base_len] | |
| before_len = base_len - position | |
| after_len = length - before_len | |
| _replace(data, position, chunk[:before_len]) | |
| _replace(data, 0, chunk[before_len:]) | |
| else: | |
| _replace(data, position, chunk) | |
| position += (length + skip_size) | |
| if position >= base_len: | |
| position = position % base_len | |
| skip_size += 1 | |
| #print position, skip_size #, data | |
| return data, position, skip_size | |
| def part_one(lengths, base_len): | |
| data = list(range(base_len)) | |
| position = 0 | |
| skip_size = 0 | |
| data, position, skip_size = hash_list( | |
| (int(n) for n in lengths.split(",")), | |
| data, | |
| 0, | |
| 0, | |
| ) | |
| return data[0]*data[1] | |
| print part_one("3,4,1,5", 5) | |
| print part_one(INPUT, 256) | |
| def part_two(lengths): | |
| lengths = [ord(c) for c in lengths] + [17, 31, 73, 47, 23] | |
| data = list(range(256)) | |
| position = 0 | |
| skip_size = 0 | |
| for __ in range(64): | |
| data, position, skip_size = hash_list(lengths, data, position, skip_size) | |
| dense = [] | |
| for offset in range(0, 256, 16): | |
| chunk = data[offset:offset+16] | |
| d = chunk[0] | |
| for v in chunk[1:]: | |
| d = d ^ v | |
| dense.append(d) | |
| return "".join("%02x" % d for d in dense) | |
| print part_two(INPUT) | |
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