Good Blogs

https://www.luogu.com.cn/blog/virus2017/shuweidp 数位DP
https://www.cnblogs.com/Phoenix41/p/12537234.html 组合数学选讲
https://www.xht37.com/my-oi/ noi Ag选手xht的blog 记录了一些一句话概括、tricks还有一些经验

https://www.cnblogs.com/zzqsblog/ ioi Au选手zzq的blog 解题思路很清楚
https://www.cnblogs.com/Winniechen/ 似乎是noi Au XJ cly的blog?
https://www.cnblogs.com/zhouzhendong/ noi Au XJ zzd的blog
https://www.cnblogs.com/zkyJuruo/ 巨佬ZAK的BLOG!!!
https://www.cnblogs.com/RabbitHu/ 浅显易懂的blog，好评
https://zhuanlan.zhihu.com/p/40505277 FFT NTT
https://www.zhihu.com/question/22298352 卷积