My Advent of Code solutions in Python.
kevinyap.ca/2019/12/going-fast-in-advent-of-code/
advent-of-code
python
Add 2021/10
+51
+51
2021/day10.py
+51
2021/day10.py
···
1
+
import fileinput
2
+
3
+
RIGHT_TO_LEFT = {
4
+
'}': '{',
5
+
']': '[',
6
+
')': '(',
7
+
'>': '<',
8
+
}
9
+
10
+
LEFT_TO_RIGHT = {v: k for k, v in RIGHT_TO_LEFT.items()}
11
+
12
+
ILLEGAL_POINTS = {
13
+
')': 3,
14
+
']': 57,
15
+
'}': 1197,
16
+
'>': 25137,
17
+
}
18
+
19
+
PART_2_POINTS = {
20
+
')': 1,
21
+
']': 2,
22
+
'}': 3,
23
+
'>': 4,
24
+
}
25
+
26
+
part_1 = 0
27
+
part_2_scores = []
28
+
29
+
for line in fileinput.input():
30
+
stk = []
31
+
is_incomplete = True
32
+
33
+
for c in line.strip():
34
+
if c in RIGHT_TO_LEFT.values():
35
+
stk.append(c)
36
+
else:
37
+
p = stk.pop()
38
+
if RIGHT_TO_LEFT[c] != p:
39
+
is_incomplete = False
40
+
part_1 += ILLEGAL_POINTS[c]
41
+
42
+
if is_incomplete:
43
+
score = 0
44
+
for s in stk[::-1]:
45
+
score *= 5
46
+
score += PART_2_POINTS[LEFT_TO_RIGHT[s]]
47
+
48
+
part_2_scores.append(score)
49
+
50
+
print "Part 1:", part_1
51
+
print "Part 2:", sorted(part_2_scores)[len(part_2_scores)//2]