代码

unsigned b[100000005], c[0x20000];

void sort(unsigned *a, int n)
{
	unsigned *c1 = c, *c2 = c1 + 0x10000;
	
	for (int i = 0; i != n; ++i)
		++c1[a[i] & 0xFFFF], ++c2[a[i] >> 16];
	for (int i = 1; i != 0x10000; ++i)
		c1[i] += c1[i - 1];
	for (int i = 1; i != 0x10000; ++i)
		c2[i] += c2[i - 1];
	for (int i = n - 1; i >= 0; --i)
		b[--c1[a[i] & 0xFFFF]] = a[i];
	for (int i = n - 1; i >= 0; --i)
		a[--c2[b[i] >> 16]] = b[i];
}

评测结果