代码

void my_memset(char *a, char c, unsigned n) {
	typedef unsigned long long int ull;
	char b[8];
	for(int i=0;i<8;i++)b[i]=c;
	ull x=(*ull)(b);
	unsigned m=n/8;
	for(unsigned i = 0; i < m; i++)
		((ull*)(a))[i] = x;
	for(unsigned i = m*8; i < n; i++)
		a[i] = c;
}

评测结果