eldridge.cam
Advent of Code solutions
more micro optimizations
+20
-20
2025/9/p2.tri
+20
-20
2025/9/p2.tri
···
12
12
func is_vertical [x1, _]:[x2, _] = x1 == x2
13
13
14
14
func collide p1:p2 [bx1, by1]:[bx2, by2] =
15
-
let [px1, px2] = sort [x p1, x p2],
16
-
let [py1, py2] = sort [y p1, y p2],
15
+
let px1:px2 = if x p1 < x p2 then x p1:x p2 else x p2:x p1,
16
+
let py1:py2 = if y p1 < y p2 then y p1:y p2 else y p2:y p1,
17
17
px1 < bx2 && px2 > bx1 && py1 < by2 && py2 > by1
18
18
19
19
func x [a, _] = a
···
58
58
dbg!(min_x:max_x)
59
59
dbg!(min_y:max_y)
60
60
61
-
let x_ranges = zip xs (tail xs)
62
-
let mut i = 0
63
-
while i < length x_ranges {
64
-
let x1:x2 and range = x_ranges.i
65
-
i += 1
66
-
if x1 == x2 { continue unit }
67
-
let [y1, .._, y2] = horizontals
68
-
|> filter (contains_by x range)
69
-
|> map (y << left)
70
-
|> sort
71
-
push!(illegal, [x1, min_y]:[x2, y1])
72
-
push!(illegal, [x1, y2]:[x2, max_y])
73
-
}
74
-
dbg!('illegal(length illegal))
75
-
76
61
let y_ranges = zip ys (tail ys)
77
62
let mut i = 0
78
63
while i < length y_ranges {
···
82
67
let [x1, .._, x2] = verticals
83
68
|> filter (contains_by y range)
84
69
|> map (x << left)
85
-
|> sort
86
70
push!(illegal, [min_x, y1]:[x1, y2])
87
71
push!(illegal, [x2, y1]:[max_x, y2])
88
72
}
89
73
dbg!('illegal(length illegal))
90
74
75
+
let x_ranges = zip xs (tail xs)
76
+
let mut i = 0
77
+
while i < length x_ranges {
78
+
let x1:x2 and range = x_ranges.i
79
+
i += 1
80
+
if x1 == x2 { continue unit }
81
+
let [y1, .._, y2] = horizontals
82
+
|> filter (contains_by x range)
83
+
|> map (y << left)
84
+
push!(illegal, [x1, min_y]:[x2, y1])
85
+
push!(illegal, [x1, y2]:[x2, max_y])
86
+
}
87
+
dbg!('illegal(length illegal))
88
+
91
89
# Then we just run standard collision of the area boxes with those
92
90
let mut best = 0
93
91
let mut i = 0
···
98
96
let a = points.i
99
97
let b = points.j
100
98
let candidate = area a b
101
-
if candidate > best && !(any (collide (a:b)) illegal) {
102
-
best = candidate
99
+
if candidate > best {
100
+
if !(any (collide (a:b)) illegal) {
101
+
best = candidate
102
+
}
103
103
}
104
104
j += 1
105
105
}