https://ac.nowcoder.com/acm/contest/327/H
C++版本一
std
题解:素数 构造 欧拉函数
参考文章:https://blog.csdn.net/weixin_43272781/article/details/85558253
#include <bits/stdc++.h>
using namespace std;
#define maxn 1000000
int pri[maxn+5];
void getprime()
{
int i,j;
for (i=2;i<=maxn;i++)
{
if (pri[i]==0) pri[++pri[0]]=i;
for (j=1;j<=pri[0] && pri[j]<=maxn/i;j++)
{
pri[pri[j]*i]=1;
if (i%pri[j]==0) break;
}
}
}
int main()
{
getprime();
for (int i=1;i<=2000;i++)
{
printf("%d\n",pri[i]*pri[4001-i]);
}
return 0;
}