AdventOfCode2024/src/ClawContraption.cpp

111 lines
2.9 KiB
C++

// Solutions to the Advent Of Code 2024.
// Copyright (C) 2025 Stefan Müller
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software
// Foundation, either version 3 of the License, or (at your option) any later
// version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <http://www.gnu.org/licenses/>.
#include <aoc/ClawContraption.hpp>
#include <sstream>
const std::string ClawContraption::getPuzzleName() const
{
return "Claw Contraption";
}
const int ClawContraption::getPuzzleDay() const
{
return 13;
}
void ClawContraption::processDataLine(const std::string& line)
{
if (!line.empty())
{
std::istringstream stream{ line };
std::string token;
char c;
int x;
int y;
stream >> token;
if (token == "Button")
{
stream >> c;
std::getline(stream, token, '+');
stream >> x;
std::getline(stream, token, '+');
stream >> y;
if (c == 'A')
{
buttonA_ = { x, y };
}
else
{
buttonB_ = { x, y };
}
}
else
{
std::getline(stream, token, '=');
stream >> x;
std::getline(stream, token, '=');
stream >> y;
part1 += calcTokenCost(buttonA_, buttonB_, { x, y }, 0);
part2 += calcTokenCost(buttonA_, buttonB_, { x, y }, getConversionCorrection());
}
}
}
void ClawContraption::finish()
{
}
constexpr int ClawContraption::getNMaxButtonPushes()
{
return 100;
}
constexpr int ClawContraption::getButtonACost()
{
return 3;
}
constexpr int ClawContraption::getButtonBCost()
{
return 1;
}
constexpr long long int ClawContraption::getConversionCorrection()
{
return 10000000000000;
}
long long int ClawContraption::calcTokenCost(const Point2& buttonA, const Point2& buttonB, const Point2& prize,
const long long int offset)
{
long long int p{ (prize.y + offset) * buttonB.x - (prize.x + offset) * buttonB.y };
long long int q{ buttonA.y * buttonB.x - buttonA.x * buttonB.y };
long long int a{ p / q };
if (a * q != p || (offset == 0 && a > getNMaxButtonPushes()))
{
return 0;
}
long long int r{ prize.x + offset - a * buttonA.x };
long long int b{ r / buttonB.x };
if (b * buttonB.x != r || (offset == 0 && b > getNMaxButtonPushes()))
{
return 0;
}
return a * getButtonACost() + b * getButtonBCost();
}