Files
AdventOfCode/2025/day3.hpp
2025-12-03 07:15:40 +00:00

99 lines
2.1 KiB
C++

#include "aoc.hpp"
#include <algorithm>
class Day03 : public AOCDay
{
public:
Day03() {}
~Day03() {}
int Day() override {return 3;}
uint64_t PartOne(File& f) override
{
uint64_t totalJoltage = 0;
for (auto bank : f.Lines())
{
int joltage = 0;
// find biggest (can't be last)
int biggest = 0;
int biggestIndex = 0;
for (int i = 0; i < bank.length() - 1; i++)
{
if (bank[i] - '0' > biggest)
{
biggest = bank[i] - '0';
biggestIndex = i + 1;
}
}
joltage = biggest;
joltage *= 10;
biggest = 0;
for (int i = biggestIndex; i < bank.length(); i++)
{
if (bank[i] - '0' > biggest)
{
biggest = bank[i] - '0';
}
}
joltage += biggest;
totalJoltage += joltage;
}
return totalJoltage;
}
std::pair<int,int> FindNextBiggestNoOffset(std::string bank, int startOffset, int endOffset)
{
int biggest = 0, biggestIndex = 0;
for (int i = startOffset; i < bank.length() - endOffset; i++)
{
if (bank[i] - '0' > biggest)
{
biggest = bank[i] - '0';
biggestIndex = i + 1;
}
}
return {biggest, biggestIndex};
}
uint64_t PartTwo(File& f) override
{
uint64_t totalJoltage = 0;
for (auto bank : f.Lines())
{
uint64_t joltage = 0;
int start = 0;
for (int i = 0; i < 12; i++)
{
joltage *= 10;
auto res = FindNextBiggestNoOffset(bank, start, 12 - i);
start = res.second;
joltage += res.first - '0';
}
std::cout << joltage << std::endl;
totalJoltage += joltage;
}
return totalJoltage;
}
};
ADD_AOC_DAY(Day03);