代码

#include <bits/stdc++.h>

using ll = long long;

using namespace std;

const int N = 1000000001;

alignas(8) char a[N];

void my_memset(char *a, char c, unsigned n) {
	memset(a , c , n);
}

signed main(){
	my_memset(a , 'a' , 1000000000);
	return 0;
}

评测结果