代码

void my_memset(char *a, char c, unsigned n)
{
	char *end = a + n;
	while((unsigned) a % 4) *a++ = c;
	unsigned pat = (unsigned) c << 24 | (unsigned) c << 16 | (unsigned) c << 8 | (unsigned) c;
	while(a + 4 < end)
	{
		*(unsigned *) a = pat;
		a += 4;
	}
	while(a < end) *a++ = c;
}

评测结果