代码

unsigned b[10000], cnt[256];

void songsongsong(unsigned *a,unsigned n){
	unsigned *A=a, *B=b, *T;
	{
		register unsigned i;
		for (i=0;i<256;++i) cnt[i]=0;
		for (i=0;i<n;++i) ++cnt[A[i]&255];
		for (i=1;i<256;++i) cnt[i]+=cnt[i-1];
		for (i=n-1;~i;--i) B[--cnt[A[i]&255]]=A[i];
		T=A; A=B; B=T;
	}
	{
		register unsigned i;
		for (i=0;i<256;++i) cnt[i]=0;
		for (i=0;i<n;++i) ++cnt[A[i]>>8&255];
		for (i=1;i<256;++i) cnt[i]+=cnt[i-1];
		for (i=n-1;~i;--i) B[--cnt[A[i]>>8&255]]=A[i];
		T=A; A=B; B=T;
	}
	{
		register unsigned i;
		for (i=0;i<256;++i) cnt[i]=0;
		for (i=0;i<n;++i) ++cnt[A[i]>>16&255];
		for (i=1;i<256;++i) cnt[i]+=cnt[i-1];
		for (i=n-1;~i;--i) B[--cnt[A[i]>>16&255]]=A[i];
		T=A; A=B; B=T;
	}
	{
		register unsigned i;
		for (i=0;i<256;++i) cnt[i]=0;
		for (i=0;i<n;++i) ++cnt[A[i]>>24&255];
		for (i=1;i<256;++i) cnt[i]+=cnt[i-1];
		for (i=n-1;~i;--i) B[--cnt[A[i]>>24&255]]=A[i];
		T=A; A=B; B=T;
	}
}

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

评测结果