#include <fstream>
#include <iostream>
#include <sstream>
#include <vector>

std::vector<int> getCrabs(const std::string &file_name) {
    std::vector<int> crabs;

    std::ifstream file(file_name);
    std::string str;
    std::getline(file, str);
    int tmp{};
    char tmp_char{};
    std::stringstream ss(str);
    while (ss >> tmp) {
        if (tmp >= crabs.size()) {
            crabs.resize(tmp + 1);
        }
        crabs[tmp] += 1;
        ss >> tmp_char;
    }
    return crabs;
}

uint64_t diff(uint64_t a, uint64_t b) {
    if (a < b) {
        return b - a;
    }
    return a - b;
}

static std::vector<uint64_t> fuel_cost{ 0 };

uint64_t increasingFuel(uint64_t a, uint64_t b) {
    auto difference = diff(a, b);
    while (fuel_cost.size() <= difference) {
        fuel_cost.push_back(fuel_cost.back() + fuel_cost.size());
    }
    return fuel_cost[difference];
}

uint64_t leastFuelCrabs(const std::vector<int> &crabs, bool increasing_fuel) {
    uint64_t least = -1;
    for (uint64_t i = 0; i < crabs.size(); i++) {
        uint64_t fuel = 0;
        for (uint64_t j = 0; j < crabs.size(); j++) {
            if (!increasing_fuel) {
                fuel += diff(j, i) * crabs[j];
            } else {
                fuel += increasingFuel(j, i) * crabs[j];
            }
        }
        if (fuel < least) {
            least = fuel;
        }
    }
    return least;
}

uint64_t part1(const std::vector<int> &crabs) {
    return leastFuelCrabs(crabs, false);
}

uint64_t part2(const std::vector<int> &crabs) {
    return leastFuelCrabs(crabs, true);
}

int main(int argc, char **argv) {
    if (argc < 2) {
        std::cerr << "You must provide input file!" << std::endl;
        return 1;
    }
    auto crabs = getCrabs(argv[1]);
    std::cout << "The least fuel crabs have to use is \033[91;1m"
              << part1(crabs) << "\033[0m." << std::endl;
    std::cout << "The least fuel crabs have to use with correctly computed "
                 "consumption is \033[91;1m"
              << part2(crabs) << "\033[0m." << std::endl;
    return 0;
}