radi sort

radix-sort.cpp

void radix_sort(unsigned *begin, unsigned *end)
{
    unsigned *begin1 = new unsigned[end - begin];
    unsigned *end1 = begin1 + (end - begin);

    for (unsigned shift = 0; shift < 32; shift += 8) {
        size_t count[0x100] = {};
        for (unsigned *p = begin; p != end; p++)
            count[(*p >> shift) & 0xFF]++;

        unsigned *bucket[0x100], *q = begin1;
        for (int i = 0; i < 0x100; q += count[i++])
            bucket[i] = q;

        for (unsigned *p = begin; p != end; p++)
            *bucket[(*p >> shift) & 0xFF]++ = *p;

        std::swap(begin, begin1);
        std::swap(end, end1);
    }

    delete[] begin1;
}