My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add knot_hash() to utils.py
+30
-1
+1
-1
2017/starter.py
+1
-1
2017/starter.py
···
6
6
from collections import Counter, deque, namedtuple # NOQA
7
7
from itertools import count, product, permutations, combinations, combinations_with_replacement # NOQA
8
8
9
-
from utils import (parse_line, mul, all_unique, factors, memoize, primes, new_table, md5, sha256, # NOQA
9
+
from utils import (parse_line, mul, all_unique, factors, memoize, primes, new_table, md5, sha256, knot_hash, # NOQA
10
10
Point, DIRS, DIRS_4, DIRS_8) # NOQA
11
11
12
12
# Itertools Functions:
+29
2017/utils.py
+29
2017/utils.py
···
96
96
return s.hexdigest()
97
97
98
98
99
+
def knot_hash(msg):
100
+
lengths = [ord(x) for x in msg] + [17, 31, 73, 47, 23]
101
+
sparse = range(0, 256)
102
+
pos = 0
103
+
skip = 0
104
+
105
+
for _ in range(64):
106
+
for l in lengths:
107
+
for i in range(l // 2):
108
+
x = (pos + i) % len(sparse)
109
+
y = (pos + l - i - 1) % len(sparse)
110
+
sparse[x], sparse[y] = sparse[y], sparse[x]
111
+
112
+
pos = pos + l + skip % len(sparse)
113
+
skip += 1
114
+
115
+
sparse = sparse
116
+
dense = []
117
+
118
+
for i in range(16):
119
+
res = 0
120
+
for j in range(0, 16):
121
+
res ^= sparse[(i * 16) + j]
122
+
123
+
dense.append(res)
124
+
125
+
return ''.join('%02x' % x for x in dense)
126
+
127
+
99
128
@total_ordering
100
129
class Point:
101
130
"""Simple 2-dimensional point."""