代码

#include <iostream>
#include <algorithm>
#include <vector>
#include <array>
using namespace std;

template<int RADIX_LEN=8,typename Iter>
void radix_sort(Iter begin,Iter end)
{
    using DataTy=uint32_t;
    constexpr int RADIX = 1<<RADIX_LEN;
    static_assert(sizeof(DataTy)==4);
    std::array<std::vector<DataTy>,RADIX> bucket;
    for(int i=0;i<32/RADIX_LEN;i++)
    {
        for(auto it=begin;it!=end;++it)
        {
            DataTy num=*it;
            bucket[(num>>i*RADIX_LEN)%RADIX].push_back(num);
        }
        auto it=begin;
        for(auto &&v:bucket)
        {
            for(auto num:v)
            {
                *it=num;
                ++it;
            }
            v.clear();
        }
        //bucket.clear();
    }
}

void sort(unsigned *a, int n) {
	radix_sort(a, a + n);
}

评测结果