/*
VIM: let b:lcppflags="-std=c++2a -O2 -pthread -I."
VIM: let b:wcppflags="/O2 /EHsc /DWIN32"
VIM-: let b:argv=""
*/
#include <iostream>
#include <exception>
#include <chrono>
#include <type_traits>
#include <iomanip>


template <typename T>
constexpr T negabinary(T v){
    static_assert(std::is_integral_v<T>, "Only integral types expected.");
    const T base = -2;
    const T abs_base = abs(base);
    std::make_unsigned_t<T> n = 0;
    int i = 0;
    while ( v ){
        T r = v % base;
        v /= base;
        if ( r < 0){
            v +=1;
            r = abs_base - r;
        }
        n |= std::make_unsigned_t<T>(r) << i;
        ++i;
    }
    return n;
}


int main ( void )
{try{
    auto begin = std::chrono::high_resolution_clock::now();


    for (int i = -16; i < 17; ++i){
        std::cout << std::setbase(10) << i << " == " << std::setbase(16) << std::showbase << negabinary(i) << std::endl;
    }
    //std::cout << negabinary(2.) << std::endl;

    auto end = std::chrono::high_resolution_clock::now();
    std::chrono::duration<double> seconds = end - begin;
    std::cout << "Time: " << seconds.count() << std::endl;
    return 0;
}
catch ( const std::exception& e )
{
    std::cerr << std::endl
            << "std::exception(\"" << e.what() << "\")." << std::endl;
    return 2;
}
catch ( ... )
{
    std::cerr  << std::endl
            << "unknown exception." << std::endl;
    return 1;
}}