#include <boost/timer.hpp>
#include <iostream>

int test(int i)
{
    switch (i)
    {
        case 1:     return 0;
        case 4:     return 1;
        case 9:     return 2;
        case 16:    return 3;
        case 25:    return 4;
        case 36:    return 5;
        case 49:    return 6;
        case 88:    return 7;
        default:    return -1;
    }
}

int const n = 8;
int in[] = { 1,4,9,16,25,36,49,88 };

//1,4,6,0,3,7,2

int g;

typedef unsigned long ub4;
typedef unsigned char ub1;

ub1 tab[] = {
  0,  2,  2,  7,  5,  0,  5,  0,};

/* The hash function */
ub4 phash(ub4 val)
{
  ub4 a, b, rsl;
  b = (val >> 3) & 0x7;
  a = ((val << 31) >> 29);
  rsl = (a^tab[b]);
  return rsl;
}

int look[] = {0,0,0,0,0,0,0};

int
main()
{
    {
        boost::timer t;
        for (int i = 0; i < 100000000; ++i)
        {
            g = test(in[i & 7]);
//            if (g != i & 7)
//            {
//                std::cout << "switch error at:" << i << ", expected: " <<  (i & 7) << " got: " << g << std::endl;
//                break;
//            }
        }

        double el = t.elapsed();
        std::cout << "switch took " << el << " seconds" << std::endl;
    }

    {
        for (int i = 0; i < 8; ++i)
        {
            std::cout << i << ", " << in[i] << ", " << phash(in[i]) << std::endl;
            look[phash(in[i])] = i;
        }

        std::cout << std::endl;
        std::cout << std::endl;

        for (int i = 0; i < 8; ++i)
        {
            std::cout << look[i] << std::endl;
        }

        std::cout << std::endl;
        std::cout << std::endl;

        boost::timer t;
        for (int i = 0; i < 100000000; ++i)
        {
            g = look[phash(in[i & 7])];
//            std::cout << i << ", " << in[i & 7] << ", " << g << std::endl;
//            if (g != i % n)
//            {
//                std::cout << "phash error at:" << i << ", expected: " <<  (i & 7) << " got: " << g << std::endl;
//                break;
//            }
        }

        double el = t.elapsed();
        std::cout << "phash took " << el << " seconds" << std::endl;
    }
}