Day 10, 2017 - Parts I & II

Author: scottshepard

2017/day10.py

@@ -0,0 +1,72 @@
+import os
+
+class KnotHash:
+
+	def __init__(self, nums, input):
+		self.nums = nums
+		self.input = input
+		self.pos = 0
+		self.skip_size = 0
+
+	def dense_hash(self):
+		sh = self.sparse_hash()
+		dh = [None] * 16
+		for i in list(range(16)):
+			section = [sh[j] for j in list(range(i*16, (i+1)*16))]
+			result = section[0]
+			for j in list(range(1, 16)):
+				result = result ^ section[j]
+			dh[i] = str(format(result, '02x'))
+		return ''.join(dh)
+
+	def sparse_hash(self):
+		for i in list(range(64)):
+			ascii_ints = self.string_ascii_converter(list(self.input)) + [17, 31, 73, 47, 23]
+			self.nums = self.knot_hash_round(self.nums, ascii_ints, self.pos, self.skip_size)
+		return self.nums
+
+	def knot_hash_simple(self):
+		rev_len_list = [int(d) for d in self.input.split(',')]
+		return self.knot_hash_round(self.nums, rev_len_list)
+
+	def knot_hash_round(self, nums, rev_len_list, pos=0, skip_size=0):
+		if len(rev_len_list) == 0:
+			return nums
+		rev_len = rev_len_list.pop(0)
+		hashed_nums = self.knot_hash_step(nums, rev_len, pos)
+		pos = (pos + rev_len + skip_size) % len(nums)
+		skip_size += 1
+		self.pos = pos
+		self.skip_size = skip_size
+		return self.knot_hash_round(hashed_nums, rev_len_list, pos, skip_size)
+
+	def knot_hash_step(self, nums, rev_len, pos):
+		i_in_rev = [i % len(nums) for i in list(range(pos, pos + rev_len))]
+		rev_lst = self.rev([nums[i] for i in i_in_rev])
+		i_not_in_rev = list(set(list(range(len(nums)))) - set(i_in_rev))
+		lst = [None] * (len(nums))
+		for i in list(range(len(i_in_rev))):
+			rev_i = i_in_rev[i]
+			lst[rev_i] = rev_lst[i]
+		for i in i_not_in_rev:
+			lst[i] = nums[i]
+		return lst
+
+	def rev(self, l):
+		return list(reversed(l))
+
+	def string_ascii_converter(self, string):
+		return [ord(c) for c in list(string)]
+
+if __name__ == '__main__':    
+    test_data = '3,4,1,5'
+    test_nums = [0, 1, 2, 3, 4]
+    print(KnotHash(test_nums, test_data).knot_hash_simple())
+
+    input = '189,1,111,246,254,2,0,120,215,93,255,50,84,15,94,62'
+    hashed = KnotHash(list(range(256)), input).knot_hash_simple()
+    print(hashed[0] * hashed[1])
+
+    kh = KnotHash(list(range(256)), input)
+    print(kh.dense_hash())
+