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#include <algorithm>
#include <iostream>
#include <memory>
#include <fstream>
#include <vector>
#include <array>
#include <tuple>
#include "util.h"
using Lens = std::pair<std::string,int>;
using Box = std::vector<Lens>;
using Boxes = std::array<Box,256>;
struct Cmd
{
protected:
int boxi_;
std::string label_;
public:
Cmd(const std::string& label) : boxi_{ hash(label) }, label_{label}
{
}
virtual void apply(Boxes& boxes) const
{
auto& box = boxes[boxi_];
auto has_same_label = [this](const auto& lens) { return lens.first == label_; };
if (auto lens = std::find_if(box.cbegin(), box.cend(), has_same_label);
lens != box.cend())
{
box.erase(lens);
}
}
static int hash(const std::string& label)
{
int hash{};
for (unsigned char c : label)
{
hash += c;
hash *= 17;
hash %= 256;
}
return hash;
}
};
class Add : public Cmd
{
int focal_;
public:
Add(const std::string& label, int focal) : Cmd(label), focal_{ focal }
{
}
void apply(Boxes& boxes) const override
{
auto& box = boxes[boxi_];
auto has_same_label = [this](const auto& lens) { return lens.first == label_; };
if (auto lens = std::find_if(box.begin(), box.end(), has_same_label);
lens != box.end())
{
lens->second = focal_;
}
else
{
box.push_back({ label_, focal_ });
}
}
};
int power(const Boxes& boxes)
{
int power{};
for (int b = 0; b < boxes.size(); ++b)
{
for(int l = 0; l < boxes[b].size(); ++l)
{
power += (b + 1) * (l + 1) * boxes[b][l].second;
}
}
return power;
}
std::vector<std::unique_ptr<Cmd>> parse(const char* file)
{
using namespace util::separators;
std::vector<std::unique_ptr<Cmd>> cmds;
if (std::ifstream input{ file }; input.is_open())
{
std::string line;
std::getline(input,line);
std::string_view view{ line };
auto to_cmd = [&cmds](std::string_view& str)
{
auto c{ str.find_first_of("=-") };
std::string label{ str.substr(0, c) };
if (str[c] == '-')
{
cmds.push_back(std::make_unique<Cmd>(label));
}
else
{
int focal = std::stoi( std::string{ str.substr(c + 1) } );
cmds.push_back(std::make_unique<Add>(label, focal));
}
};
util::accumulate<COMMA>(view, to_cmd);
}
return cmds;
}
int main(int argc, char* argv[])
{
Boxes boxes;
for (const auto& cmd : parse(argv[1]))
{
cmd->apply(boxes);
}
std::cout << power(boxes) << std::endl;
return 0;
}
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