1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
#include "aoc.h"
#include <deque>
namespace aoc2022 {
static int maxx = 0;
static int maxy = 0;
static int maxz = 0;
bool is_valid(droplet d, cube& c) {
bool bx = d.x >= 0 && d.x < maxx + 1;
bool by = d.y >= 0 && d.y < maxy + 1;
bool bz = d.z >= 0 && d.z < maxz + 1;
return bx && by && bz && c.get(d.x, d.y, d.z) == 0;
}
// flood
void flood(cube& c) {
std::deque<droplet> q;
c.get(0, 0, 0) = -1;
q.push_back(droplet{0, 0, 0});
while (!q.empty()) {
auto s = q.size();
while (s-- > 0) {
auto d = q.front();
q.pop_front();
droplet ds[] = {
{d.x + 1, d.y, d.z}, {d.x - 1, d.y, d.z}, {d.x, d.y + 1, d.z},
{d.x, d.y - 1, d.z}, {d.x, d.y, d.z + 1}, {d.x, d.y, d.z - 1},
};
for (auto& dx : ds) {
if (is_valid(dx, c)) {
c.get(dx.x, dx.y, dx.z) = -1;
q.push_back(dx);
}
}
}
}
}
std::pair<int, int> day18(line_view file) {
std::vector<droplet> ds;
per_line(file, [&ds](line_view lv) {
droplet d{lv};
maxx = std::max(maxx, d.x);
maxy = std::max(maxy, d.y);
maxz = std::max(maxz, d.z);
ds.emplace_back(d);
return true;
});
cube c{maxx + 1, maxy + 1, maxz + 1};
for (auto& d : ds) {
c.get(d.x, d.y, d.z) = 1;
}
flood(c);
int t0{0}, t1{0};
std::vector<droplet> dx;
c.traverse([&t0, &dx, &c](int x, int y, int z) {
if (c.get(x, y, z) == 1) {
t0 += 6;
t0 -= c.get(x - 1, y, z) == 1 ? 1 : 0;
t0 -= c.get(x + 1, y, z) == 1 ? 1 : 0;
t0 -= c.get(x, y - 1, z) == 1 ? 1 : 0;
t0 -= c.get(x, y + 1, z) == 1 ? 1 : 0;
t0 -= c.get(x, y, z - 1) == 1 ? 1 : 0;
t0 -= c.get(x, y, z + 1) == 1 ? 1 : 0;
}
if (c.get(x, y, z) == 0) {
dx.emplace_back(x, y, z);
}
});
for (auto& d : dx) {
c.get(d.x, d.y, d.z) = 1;
}
c.traverse([&t1, &c](int x, int y, int z) {
if (c.get(x, y, z) == 1) {
t1 += 6;
t1 -= c.get(x - 1, y, z) == 1 ? 1 : 0;
t1 -= c.get(x + 1, y, z) == 1 ? 1 : 0;
t1 -= c.get(x, y - 1, z) == 1 ? 1 : 0;
t1 -= c.get(x, y + 1, z) == 1 ? 1 : 0;
t1 -= c.get(x, y, z - 1) == 1 ? 1 : 0;
t1 -= c.get(x, y, z + 1) == 1 ? 1 : 0;
}
});
// printf("%d %d\n", t0, t1);
return {t0, t1};
}
} // namespace aoc2022
|
