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#include "aoc.h"
#include <algorithm>
#include <unordered_map>
#include <vector>
namespace aoc2019 {
star* find(std::unordered_map<line_view, star*>& stars, line_view lv) {
auto it = stars.find(lv);
star* s = nullptr;
if (it == stars.end()) {
s = new star{lv};
stars.insert({lv, s});
} else {
s = it->second;
}
// std::cout << s->name << std::endl;
return s;
}
void count(star* s, std::vector<star*>& vs, int* total, std::vector<star*>& v1, std::vector<star*>& v2) {
// std::cout << s->name << std::endl;
if (s->orbits.size() > 0) {
std::vector<star*> orbits{s->orbits.begin(), s->orbits.end()};
for (auto& x : orbits) {
vs.push_back(x);
count(x, vs, total, v1, v2);
vs.pop_back();
}
}
if (s->name == "YOU") {
v1 = vs;
}
if (s->name == "SAN") {
v2 = vs;
}
*total += vs.size();
}
void check(std::vector<star*> vs) {
std::for_each(vs.begin(), vs.end(), [](star* s) { std::cout << s->name << " <- "; });
std::cout << std::endl;
}
template <typename T>
static size_t common(const std::vector<T>& v1, const std::vector<T>& v2) {
size_t i{0};
while (i < v1.size() && i < v2.size()) {
if (v1[i] != v2[i]) {
return i;
}
i++;
}
return i;
}
std::pair<int, int> day6(line_view file) {
std::unordered_map<line_view, star*> stars;
per_line(file, [&stars](line_view lv) {
const char* p = lv.contains(")");
star* s1 = find(stars, line_view{lv.line, p});
star* s2 = find(stars, line_view{p + 1, lv.line + lv.length - 1});
s1->orbits.insert(s2);
return true;
});
int total{0};
std::vector<star*> vs;
std::vector<star*> v1;
std::vector<star*> v2;
count(stars["COM"], vs, &total, v1, v2);
// check(v1);
// check(v2);
// printf("%zu %zu %zu\n", common(v1, v2), v1.size(), v2.size());
size_t c = common(v1, v2);
return {total, (v1.size() - c - 1) + (v2.size() - c - 1)};
}
} // namespace aoc2019
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