代码

#include <cstdlib>
void sort(unsigned* a,int n) {
	unsigned* b=(unsigned*)malloc(n<<2);
	static unsigned cnt[1<<8];
	int sum=0;	
	unsigned *x=a,*y=b,*tmp;
	for(int i=0;i<32;i+=8){
		sum=0;
		for(int j=0;j<256;++j) cnt[j]=0;
		for(int j=0;j<n;++j) ++cnt[x[j]>>i & 0xff];
		for(int j=0;j<256;++j) sum+=cnt[j],cnt[j]=sum-cnt[j];
		for(int j=0;j<n;++j) y[cnt[x[j]>>i & 0xff]++]=x[j];
		tmp=y;
		y=x;
		x=tmp;
	}
	delete b;
}

评测结果