bpavuk.neocities.org
+24
-38
src/04/solution.cxx
+24
-38
src/04/solution.cxx
···
1
#include <filesystem>
2
#include <fstream>
3
#include <print>
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#include <sstream>
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#include <string>
6
#include <vector>
···
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std::vector<std::string> data{};
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};
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-
unsigned int count_removable_rolls(Matrix &data) {
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-
auto out = 0;
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for (unsigned long row = 0; row < data.height(); ++row) {
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for (unsigned long col = 0; col < data.width(); ++col) {
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if (data[row][col] != '@') {
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-
std::print("{}", data[row][col]);
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continue;
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}
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···
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}
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}
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if (count >= 4) {
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-
std::print("{}", data[row][col]);
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continue;
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}
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std::print("x");
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out += 1;
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}
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std::println();
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}
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return out;
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}
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int remove_rolls(Matrix& data) {
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auto removed = 0;
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-
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for (unsigned long row = 0; row < data.height(); ++row) {
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for (unsigned long col = 0; col < data.width(); ++col) {
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if (data[row][col] != '@') {
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continue;
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}
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auto sur = data.get_surrounding(row, col);
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int count = 0;
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for (auto var : sur) {
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if (var == '@') {
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count += 1;
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}
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}
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if (count >= 4) {
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continue;
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}
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data.set(row, col, '.');
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removed += 1;
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}
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}
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return removed;
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}
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int main() {
···
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file.read(input.data(), input_size);
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Matrix data(input);
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long long password_part_1 = count_removable_rolls(data);
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long long password_part_2 = 0;
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auto removables = count_removable_rolls(data);
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-
while (removables > 0) {
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std::println();
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password_part_2 += remove_rolls(data);
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-
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removables = count_removable_rolls(data);
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}
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std::println("Eureka! {} / {}", password_part_1, password_part_2);
···
1
#include <filesystem>
2
#include <fstream>
3
#include <print>
4
+
#include <span>
5
#include <sstream>
6
#include <string>
7
#include <vector>
···
65
std::vector<std::string> data{};
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};
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68
+
struct Roll {
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+
unsigned long row;
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+
unsigned long col;
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+
};
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+
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+
std::vector<Roll> get_removable_rolls(Matrix &data) {
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+
std::vector<Roll> rolls{};
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for (unsigned long row = 0; row < data.height(); ++row) {
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for (unsigned long col = 0; col < data.width(); ++col) {
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if (data[row][col] != '@') {
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continue;
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}
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···
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}
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}
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if (count >= 4) {
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continue;
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}
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+
auto roll = Roll {
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+
.row = row,
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+
.col = col,
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+
};
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rolls.push_back(roll);
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}
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}
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+
return rolls;
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}
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+
int remove_rolls(Matrix &data, std::span<Roll> removables) {
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+
for (auto roll : removables) {
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+
data.set(roll.row, roll.col, '.');
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}
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+
return removables.size();
108
}
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110
int main() {
···
121
file.read(input.data(), input_size);
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123
Matrix data(input);
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+
auto removables = get_removable_rolls(data);
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126
+
long long password_part_1 = removables.size();
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long long password_part_2 = 0;
128
129
+
while (removables.size() > 0) {
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+
password_part_2 += removables.size();
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+
remove_rolls(data, removables);
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133
+
removables = get_removable_rolls(data);
134
}
135
136
std::println("Eureka! {} / {}", password_part_1, password_part_2);