Files
advent-of-code/2023/puzzle-14-01.cc
2023-12-14 09:11:36 +00:00

73 lines
1.7 KiB
C++

#include <algorithm>
#include <cstdint>
#include <cstdlib>
#include <iostream>
#include <string>
#include <vector>
using UInt = std::uint64_t;
struct Grid
{
void push_back(std::string const& row) { rows_.push_back(row); }
void roll_north()
{
for (auto row{rows_.begin() + 1}; row != rows_.end(); ++row) {
for (std::size_t col{0}; col < row->size(); ++col) {
if (row->at(col) == 'O') {
auto new_row = row - 1;
while (new_row != rows_.begin() && new_row->at(col) == '.') { --new_row; }
if (new_row->at(col) != '.') { ++new_row; }
if (new_row != row) {
new_row->at(col) = 'O';
row->at(col) = '.';
}
}
}
}
}
[[nodiscard]] auto load() const -> UInt
{
UInt load{0};
for (std::size_t row{0}; row != rows_.size(); ++row) {
auto count = std::count_if(rows_[row].begin(), rows_[row].end(),
[](char c) { return c == 'O'; });
load += count * (rows_.size() - row);
}
return load;
}
friend auto operator<<(std::ostream& os, Grid const& grid) -> std::ostream&;
private:
std::vector<std::string> rows_;
};
auto operator<<(std::ostream& os, Grid const& grid) -> std::ostream&
{
for (auto const& row : grid.rows_) { os << row << '\n'; }
return os;
}
auto main() -> int try {
std::string line;
Grid grid;
while (std::getline(std::cin, line)) {
grid.push_back(line);
}
std::cout << "Read in grid:\n" << grid;
grid.roll_north();
std::cout << "Rolled grid:\n" << grid;
std::cout << "Load: " << grid.load() << '\n';
return EXIT_SUCCESS;
}
catch (...) {
std::cerr << "Uncaught exception.\n";
return EXIT_FAILURE;
}