my aoc solutions
day 5 pt 2
+67
-1
+44
-1
src/aoc_2025/day_5.gleam
+44
-1
src/aoc_2025/day_5.gleam
···
55
55
}
56
56
57
57
pub fn pt_2(input: #(List(#(Int, Int)), List(Int))) {
58
-
todo as "part 2 not implemented"
58
+
let #(ranges, _) = input
59
+
60
+
let sum =
61
+
ranges
62
+
// |> echo
63
+
|> list.fold([], fn(processed, range) { pt_2_loop(range, processed, []) })
64
+
|> list.fold(0, fn(sum, range) {
65
+
case range {
66
+
#(0, 0) -> sum
67
+
#(start, end) -> {
68
+
sum + { { end - start } + 1 }
69
+
}
70
+
}
71
+
})
72
+
73
+
sum
74
+
}
75
+
76
+
pub fn pt_2_loop(range, processed_ranges: List(#(Int, Int)), acc) {
77
+
let #(start, end) = range
78
+
79
+
case processed_ranges {
80
+
// we've gone through all of them
81
+
// add range to acc for next round of processing
82
+
[] -> [range, ..acc]
83
+
// fully fits into a different range, we are done
84
+
[p_range, ..rest] if p_range.0 <= start && p_range.1 >= end ->
85
+
list.append([p_range, ..acc], rest)
86
+
87
+
// already processed one fits fully
88
+
[p_range, ..rest] if p_range.0 >= start && p_range.1 <= end ->
89
+
pt_2_loop(range, rest, acc)
90
+
91
+
// merge at front
92
+
[#(p_start, p_end), ..rest] if start >= p_start && start <= p_end ->
93
+
pt_2_loop(#(p_start, end), rest, acc)
94
+
95
+
// merge at end
96
+
[#(p_start, p_end), ..rest] if end >= p_start && end <= p_end ->
97
+
pt_2_loop(#(start, p_end), rest, acc)
98
+
99
+
// keep the unmatched
100
+
[unmatched, ..rest] -> pt_2_loop(range, rest, [unmatched, ..acc])
101
+
}
59
102
}
+23
test/advent_of_code_test.gleam
+23
test/advent_of_code_test.gleam
···
1
1
import aoc_2025/day_3
2
+
import aoc_2025/day_5
2
3
import gleam/int
4
+
import gleam/list
3
5
import gleeunit
4
6
import gleeunit/should
5
7
···
39
41
let answer = day_3.pt_2([bank])
40
42
should.equal(answer, 444_444_444_444)
41
43
}
44
+
45
+
pub fn day_5_pt_2_icky_test() {
46
+
[
47
+
// overlap right
48
+
[#(1, 5), #(3, 7)],
49
+
// fully fits
50
+
[#(3, 5), #(1, 7)],
51
+
[#(1, 7), #(3, 5)],
52
+
// overlap left
53
+
[#(3, 7), #(1, 5)],
54
+
55
+
[#(1, 3), #(5, 7), #(2, 6)],
56
+
57
+
[#(1, 3), #(5, 7), #(2, 6)],
58
+
[#(1, 3), #(4, 4), #(5, 7)],
59
+
]
60
+
|> list.map(fn(in) {
61
+
echo in
62
+
assert day_5.pt_2(#(in, [])) == 7
63
+
})
64
+
}