@[xzjxzjxzj](/user/751403) x=25
by HoshinoYuki @ 2023-08-03 23:15:38
你用一些办法处理掉之后肯定还要跑一遍防漏
by HoshinoYuki @ 2023-08-03 23:15:57
@[HoshinoYuki](/user/585618) 巨佬我想问一下这个遍历
```c
for(int i=5;i*i<=n;i+=6) if(n%i==0||n%(i+2)==0) return false;
```
为什么是i+=6?
为什么if条件要写n%(i+2)==0?
谢谢大佬!
by xzjxzjxzj @ 2023-08-04 10:47:25
@[xzjxzjxzj](/user/751403) 画个多行 6 列的图就能很直观地理解了 稍等我画画
by HoshinoYuki @ 2023-08-04 15:12:55
@[xzjxzjxzj](/user/751403) ![](https://cdn.luogu.com.cn/upload/image_hosting/w7ga87e5.png)
by HoshinoYuki @ 2023-08-04 15:18:57
@[HoshinoYuki](/user/585618) 膜拜巨佬!跪谢!!!
by xzjxzjxzj @ 2023-08-05 08:59:30