aoc24/d3/main.cxx
2024-12-03 14:07:43 +01:00

56 lines
1.2 KiB
C++

#include <iostream>
#include <regex>
using std::cout, std::endl;
constexpr const char content[] = {
#embed "input.txt"
};
void part_1() {
std::string input = std::string(content);
auto acc{0};
std::regex re{"mul\\((\\d+),(\\d+)\\)"};
std::smatch match;
while (std::regex_search(input, match, re)) {
int a = std::stoi(match[1].str());
int b = std::stoi(match[2].str());
acc += a * b;
input = match.suffix().str();
}
cout << acc << endl;
}
void part_2() {
std::string input = std::string(content);
auto acc{0};
std::regex re{"do\\(\\)|don't\\(\\)|mul\\((\\d+),(\\d+)\\)"};
std::smatch match;
bool enabled{true};
while(std::regex_search(input, match, re)) {
if (match[0].str() == "do()") {
enabled = true;
} else if (match[0].str() == "don't()") {
enabled = false;
} else if (enabled) {
int x = std::stoi(match[1].str());
int y = std::stoi(match[2].str());
acc += x * y;
}
input = match.suffix().str();
}
cout << acc << endl;
}
int main() {
part_1();
part_2();
return 0;
}