utils.hpp

#include <fstream>
#include <iostream>
#include <vector>
#include <iterator>
#include <algorithm>
#include <map>
#include <sstream>
#include <cmath>
#include <regex>
#include <set>

class line
{
    std::string data;

public:
    friend std::istream &operator>>(std::istream &is, line &l)
    {
        std::getline(is, l.data);
        return is;
    }
    operator std::string() const { return data; }
};

std::vector<std::string> read_input(std::istream &ifs)
{
    std::vector<std::string> lines;
    std::copy(std::istream_iterator<line>(ifs),
              std::istream_iterator<line>(),
              std::back_inserter(lines));
    return lines;
}

std::vector<std::string> read_input(const std::string &f)
{
    auto ifs = std::ifstream(f, std::ifstream::in);
    if (!ifs)
    {
        std::cerr << "Unable to open file: " << f << "\n";
        exit(-1);
    }
    return read_input(ifs);
}

std::vector<int64_t> read_ints(std::istream &ifs)
{
    std::vector<int64_t> lines;
    std::transform(std::istream_iterator<line>(ifs),
                   std::istream_iterator<line>(), std::back_inserter(lines),
                   [&](const line &l)
                   { return std::stol(l); });
    return lines;
}

std::vector<int64_t> read_ints(const std::string &f)
{
    auto ifs = std::ifstream(f, std::ifstream::in);
    if (!ifs)
    {
        std::cerr << "Unable to open file: " << f << "\n";
        exit(-1);
    }
    return read_ints(ifs);
}