代码

unsigned b[100000000], c0[256], c1[256], c2[256], c3[256];
unsigned *pos[256];

#define gao(cnt,op) \
		pos[0]=B+cnt[0];\
		for (i=1;i<256;++i) cnt[i]+=cnt[i-1], pos[i]=B+cnt[i];\
		for (i=n-1;~i;--i){\
			*(--pos[A[i] op])=A[i];\
		}\
		T=A; A=B; B=T;

void songsongsong(unsigned *a,unsigned n){
	{
		register unsigned i;
		for (i=0;i<n;++i){
			++c0[a[i]&255];
			++c1[a[i]>>8&255];
			++c2[a[i]>>16&255];
			++c3[a[i]>>24&255];
		}
	}
	
	unsigned *A=a, *B=b, *T;
	
	{
		register unsigned i;
		gao(c0,&255);
	}
	{
		register unsigned i;
		gao(c1,>>8&255);
	}
	{
		register unsigned i;
		gao(c2,>>16&255);
	}
	{
		register unsigned i;
		gao(c3,>>24&255);
	}
}

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

评测结果