blob: 41267b048f514afd5b2a69d96c6d8db8b675a19a (
plain)
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
|
#include "aoc.h"
namespace aoc2016 {
void get_number(const char** pp, int* d) {
const char* p = *pp;
while (*p >= '0' && *p <= '9') {
*d = *d * 10 + *p - '0';
p++;
}
*pp = p;
}
void get_sides(line_view lv, int is[]) {
const char* p = lv.line;
size_t i{0};
while (p < lv.line + lv.length) {
if (*p >= '0' && *p <= '9') {
get_number(&p, &is[i++]);
}
p++;
}
}
int is_triangle(int is[]) {
auto b1 = is[0] + is[1] > is[2];
auto b2 = is[0] + is[2] > is[1];
auto b3 = is[1] + is[2] > is[0];
return int(b1 && b2 && b3);
}
int has_triangle(int is[]) {
auto b1 = is[0] + is[3] > is[6];
auto b2 = is[0] + is[6] > is[3];
auto b3 = is[3] + is[6] > is[0];
auto b4 = is[1] + is[4] > is[7];
auto b5 = is[1] + is[7] > is[4];
auto b6 = is[4] + is[7] > is[1];
auto b7 = is[2] + is[5] > is[8];
auto b8 = is[2] + is[8] > is[5];
auto b9 = is[5] + is[8] > is[2];
return int(b1 && b2 && b3) + int(b4 && b5 && b6) + int(b7 && b8 && b9);
}
std::pair<int, int> day3(line_view file) {
int t0{0};
int t1{0};
size_t i{0};
const char* p = file.line;
per_line(file, [&t0, &t1, &i, &p](line_view lv) {
i++;
if (i % 3 == 0) {
int xs[9] = {0};
get_sides(line_view{p, lv.line + lv.length}, xs);
t1 += has_triangle(xs);
p = lv.line + lv.length + 1;
}
int is[3] = {0};
get_sides(lv, is);
t0 += is_triangle(is);
return true;
});
return {t0, t1};
}
} // namespace aoc2016
|
