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#include <filesystem>
#include <fstream>
#include <iostream>
#include <map>
#include <regex>
#include <set>
#include <string>
#include <vector>
using namespace std;
namespace {
struct Node {
int x, y;
int size, used, avail, percent;
[[nodiscard]]
tuple<int, int> pos() const
{
return { x, y };
}
};
vector<Node>
readNodes(const filesystem::path& filename)
{
static const regex line_regex(R"(^/dev/grid/node-x(\d+)-y(\d+)\s+(\d+)T\s+(\d+)T\s+(\d+)T\s+(\d+)%$)");
ifstream file{ filename };
vector<Node> nodes;
for ( string line; getline(file, line); ) {
smatch match;
if ( !regex_match(line, match, line_regex) ) {
continue;
}
Node node{
.x = stoi(match[1].str()), // x
.y = stoi(match[2].str()), // y
.size = stoi(match[3].str()), // size
.used = stoi(match[4].str()), // used
.avail = stoi(match[5].str()), // avail
.percent = stoi(match[6].str()) // percent
};
nodes.emplace_back(node);
}
return nodes;
}
void
part1(const vector<Node>& nodes)
{
long count = 0;
for ( size_t i = 0; i != nodes.size(); ++i ) {
if ( nodes[i].used == 0 ) {
continue;
}
for ( size_t j = 0; j != nodes.size(); ++j ) {
if ( i == j ) {
continue;
}
if ( nodes[i].used < nodes[j].avail ) {
++count;
}
}
}
cout << count << '\n';
}
void
part2(const vector<Node>& nodes)
{
using pos_type = tuple<int, int>;
map<pos_type, char> grid;
#ifdef PRINT
const auto max_y = ranges::max_element(nodes, {}, &Node::y)->y;
#endif
const auto max_x = ranges::max_element(nodes, {}, &Node::x)->x;
const auto largest = ranges::max_element(nodes, {}, &Node::avail)->avail;
const pos_type g_pos = { max_x, 0 };
const pos_type s_pos = { 0, 0 };
pos_type start{};
for ( const auto& node: nodes ) {
auto pos = node.pos();
if ( pos == s_pos ) {
grid[pos] = 'S';
}
else if ( pos == g_pos ) {
grid[pos] = 'G';
}
else if ( node.used == 0 ) {
grid[pos] = '_';
start = pos;
}
else if ( node.used >= largest ) {
grid[pos] = '#';
}
else {
grid[pos] = '.';
}
}
#ifdef PRINT
string result{};
for ( int pos_y = 0; pos_y <= max_y; ++pos_y ) {
for ( int pos_x = 0; pos_x <= max_x; ++pos_x ) {
result += grid[{ pos_x, pos_y }];
}
result += '\n';
}
cout << result << '\n';
#endif
set<pos_type> seen;
queue<tuple<pos_type, int>> queue; // position, #Schritte
queue.emplace(start, 0);
while ( !queue.empty() ) {
const auto [pos, steps] = queue.front();
queue.pop();
if ( pos == g_pos ) {
cout << steps + (5 * (max_x - 1)) << '\n';
return;
}
static const pos_type dirs[]{ { -1, 0 }, { 1, 0 }, { 0, -1 }, { 0, 1 } };
for ( const auto [dx, dy]: dirs ) {
const auto [x, y] = pos;
const pos_type new_pos{ x + dx, y + dy };
if ( !grid.contains(new_pos) || grid.at(new_pos) == '#' || seen.contains(new_pos) ) {
continue;
}
seen.insert(new_pos);
queue.emplace(new_pos, steps + 1);
}
}
}
} // namespace
int
main()
{
auto nodes = readNodes("data/day22.txt");
part1(nodes);
part2(nodes);
}
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