My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add solution for 2016/19
+55
+52
2016/day19.py
+52
2016/day19.py
···
1
+
import fileinput
2
+
3
+
4
+
class LinkedElf:
5
+
def __init__(self, num):
6
+
self.num = num
7
+
self.next = None
8
+
9
+
10
+
def adjacent_elves(num_elves):
11
+
head = LinkedElf(1)
12
+
curr = head
13
+
14
+
for i in range(2, num_elves + 1):
15
+
curr.next = LinkedElf(i)
16
+
curr = curr.next
17
+
18
+
curr.next = head
19
+
curr = head
20
+
21
+
while curr is not curr.next:
22
+
curr.next = curr.next.next
23
+
curr = curr.next
24
+
25
+
return curr.num
26
+
27
+
28
+
def circular_elves(num_elves):
29
+
seen = set()
30
+
victim = num_elves // 2
31
+
32
+
# Start with a double jump if number of elves is odd
33
+
double = (num_elves % 2) == 1
34
+
35
+
while True:
36
+
seen.add(victim)
37
+
38
+
if len(seen) == num_elves:
39
+
return victim + 1
40
+
41
+
for _ in range(2 if double else 1):
42
+
victim = (victim + 1) % num_elves
43
+
while victim in seen:
44
+
victim = (victim + 1) % num_elves
45
+
46
+
double = not double
47
+
48
+
49
+
if __name__ == '__main__':
50
+
num_elves = int(fileinput.input()[0])
51
+
print "Winning Elf in part 1:", adjacent_elves(num_elves)
52
+
print "Winning Elf in part 2:", circular_elves(num_elves)
+1
2016/inputs/19.txt
+1
2016/inputs/19.txt
···
1
+
3017957