bpavuk.neocities.org
Advent of Code 2025, done in C++
day[07]: applied nice formatting
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-96
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.clang-format
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.clang-format
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-96
src/07/solution.cxx
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src/07/solution.cxx
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#include "common/getinputpath.h"
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#include <cstddef>
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#include <format>
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#include <fstream>
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#include <string>
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#include <vector>
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void render(std::vector<std::string> &data) {
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if (data.size() < 2) {
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return;
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}
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#include "common/getinputpath.h"
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void render(std::vector<std::string>& data) {
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if (data.size() < 2) {
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return;
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}
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for (size_t i = 1; i < data.size(); ++i) {
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auto &previous = data[i - 1];
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auto ¤t = data[i];
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for (size_t i = 1; i < data.size(); ++i) {
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auto& previous = data[i - 1];
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auto& current = data[i];
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for (size_t ch = 0; ch < current.size(); ++ch) {
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char previous_ch = previous[ch];
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char current_ch = current[ch];
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if (previous_ch != 'S' && previous_ch != '|') {
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continue;
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}
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for (size_t ch = 0; ch < current.size(); ++ch) {
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char previous_ch = previous[ch];
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char current_ch = current[ch];
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if (previous_ch != 'S' && previous_ch != '|') {
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continue;
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}
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// render
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if (current_ch == '^') {
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// split
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if (ch > 0) {
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current[ch - 1] = '|';
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}
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if (ch < current.size()) {
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current[ch + 1] = '|';
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// render
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if (current_ch == '^') {
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// split
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if (ch > 0) {
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current[ch - 1] = '|';
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}
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if (ch < current.size()) {
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current[ch + 1] = '|';
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}
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} else {
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current[ch] = '|';
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}
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}
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} else {
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current[ch] = '|';
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}
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}
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}
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}
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long long count_beams_split(std::vector<std::string> &data) {
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if (data.size() < 2) {
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return 0;
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}
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auto out = 0;
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long long count_beams_split(std::vector<std::string>& data) {
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if (data.size() < 2) {
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return 0;
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}
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auto out = 0;
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for (size_t i = 1; i < data.size(); ++i) {
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auto &previous = data[i - 1];
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auto ¤t = data[i];
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for (size_t i = 1; i < data.size(); ++i) {
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auto& previous = data[i - 1];
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auto& current = data[i];
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for (size_t ch = 0; ch < current.size(); ++ch) {
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if (previous[ch] == '|' && current[ch] == '^') {
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out += 1;
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}
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for (size_t ch = 0; ch < current.size(); ++ch) {
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if (previous[ch] == '|' && current[ch] == '^') {
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out += 1;
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}
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}
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}
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}
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return out;
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return out;
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}
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struct Position {
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size_t x = 0;
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size_t y = 0;
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size_t x = 0;
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size_t y = 0;
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bool operator==(const Position& other) const {
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return x == other.x && y == other.y;
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}
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bool operator==(const Position& other) const {
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return x == other.x && y == other.y;
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}
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bool operator<(const Position& other) const {
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return y < other.y || (y == other.y && x < other.x);
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}
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bool operator<(const Position& other) const {
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return y < other.y || (y == other.y && x < other.x);
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}
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};
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long long count_possible_paths(std::vector<std::string> &data,
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Position position,
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std::map<Position, long long> &cache) {
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// TODO
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if (position.y == data.size()) { // if we reached bottom
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return 1;
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}
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long long result = 0;
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if (data[position.y][position.x] == '|' ||
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data[position.y][position.x] == 'S') {
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long long count_possible_paths(std::vector<std::string>& data,
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Position position,
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std::map<Position, long long>& cache) {
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// TODO
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if (position.y == data.size()) { // if we reached bottom
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return 1;
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}
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long long result = 0;
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if (data[position.y][position.x] == '|' ||
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data[position.y][position.x] == 'S') {
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Position new_pos{.x = position.x, .y = position.y + 1};
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result = count_possible_paths(data, new_pos, cache);
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Position new_pos{.x = position.x, .y = position.y + 1};
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result = count_possible_paths(data, new_pos, cache);
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} else if (data[position.y][position.x] == '^') {
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Position left = Position{.x = position.x - 1, .y = position.y};
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Position right = Position{.x = position.x + 1, .y = position.y};
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} else if (data[position.y][position.x] == '^') {
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Position left = Position{.x = position.x - 1, .y = position.y};
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Position right = Position{.x = position.x + 1, .y = position.y};
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// a weird workaround to satisfy some static checks. maps must be sortable.
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if (cache.contains(position)) {
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result = cache[position];
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} else {
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result = count_possible_paths(data, left, cache) +
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count_possible_paths(data, right, cache);
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// a weird workaround to satisfy some static checks. maps must
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// be sortable.
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if (cache.contains(position)) {
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result = cache[position];
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} else {
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result = count_possible_paths(data, left, cache) +
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count_possible_paths(data, right, cache);
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cache[position] = result;
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cache[position] = result;
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}
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}
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}
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return result;
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return result;
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}
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long long count_possible_paths(std::vector<std::string> &data,
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std::map<Position, long long> &cache) {
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Position start{
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.x = data[0].find_first_of('S'),
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.y = 0,
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};
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return count_possible_paths(data, start, cache);
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long long count_possible_paths(std::vector<std::string>& data,
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std::map<Position, long long>& cache) {
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Position start{
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.x = data[0].find_first_of('S'),
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.y = 0,
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};
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return count_possible_paths(data, start, cache);
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}
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// runtime on Ryzen 5 5600G: 0.003s
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int main() {
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auto data_path = get_input_path(DATA_FOLDER);
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std::ifstream data_ifstream(data_path);
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if (!data_ifstream.is_open()) {
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std::println("Cannot open the file at {}", data_path.string());
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return 1;
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}
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auto data_path = get_input_path(DATA_FOLDER);
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std::ifstream data_ifstream(data_path);
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if (!data_ifstream.is_open()) {
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std::println("Cannot open the file at {}", data_path.string());
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return 1;
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}
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std::vector<std::string> data{};
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for (std::string t; std::getline(data_ifstream, t);) {
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data.push_back(t);
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}
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std::vector<std::string> data{};
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for (std::string t; std::getline(data_ifstream, t);) {
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data.push_back(t);
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}
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render(data); // this has some great potential for TUI visualization
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render(data); // this has some great potential for TUI visualization
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long long password_part_1 = count_beams_split(data);
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long long password_part_1 = count_beams_split(data);
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std::map<Position, long long> cache{};
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long long password_part_2 = count_possible_paths(data, cache); // this one too
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std::map<Position, long long> cache{};
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long long password_part_2 =
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count_possible_paths(data, cache); // this one too
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std::println("Eureka! {} / {}", password_part_1, password_part_2);
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std::println("Eureka! {} / {}", password_part_1, password_part_2);
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return 0;
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return 0;
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}