代码

#include <algorithm>
#include<string.h>
int s[65536];
void sort(unsigned *a, int n) {
        unsigned* aa=new unsigned[n];
	for(int ii=0,i;ii<32;ii+=16){
		memset(s,0,sizeof(s));
		for(i=0;i<n;i+=8){
			++s[(a[i]>>ii)&65535];
			++s[(a[i+1]>>ii)&65535];
			++s[(a[i+2]>>ii)&65535];
			++s[(a[i+3]>>ii)&65535];
			++s[(a[i+4]>>ii)&65535];
			++s[(a[i+5]>>ii)&65535];
			++s[(a[i+6]>>ii)&65535];
			++s[(a[i+7]>>ii)&65535];
		}
		for(;i<n;++i)
			++s[(a[i]>>ii)&65535];
		for(i=1;i<65536;++i)s[i]+=s[i-1];
		for(i=n-1;i>=0;--i)aa[--s[(a[i]>>ii)&65535]]=a[i];
		std::swap(a,aa);
	}
}

评测结果