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#include "aoc.h"
namespace aoc2017 {
static 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;
}
struct record12 {
int ns[10] = {0};
bool connected = false;
void print() const noexcept {
for (auto n : ns) {
printf("%d ", n);
}
printf("\n");
}
record12(line_view lv) {
const char* p = lv.line;
int i{0};
while (p < lv.line + lv.length) {
if (*p >= '0' && *p <= '9') {
get_number(&p, &ns[i++]);
}
p++;
}
}
};
void mark_connected(size_t i, std::vector<record12>& rs, int* total) {
auto& r = rs[i];
if (!r.connected) {
*total += 1;
r.connected = true;
for (int x = 1; x < 10; x++) {
if (r.ns[x] > 0) {
mark_connected(r.ns[x], rs, total);
}
}
}
}
std::pair<int64_t, int64_t> day12(line_view file) {
std::vector<record12> rs;
per_line(file, [&rs](line_view lv) {
rs.emplace_back(lv);
return true;
});
int total{0};
mark_connected(0, rs, &total);
int t0 = total;
int t1 = 1;
for (size_t i = 1; i < rs.size() && total < (int)rs.size(); i++) {
int tx = total;
mark_connected(i, rs, &total);
if (total > tx) {
t1 += 1;
}
}
return {t0, t1};
}
} // namespace aoc2017
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