TyRant的博客

Basic Challenges01-Error Based-Single quotesError Based: 可以通过报错知道闭合方式> paylod: ?id=1') and ;--+源码拼接后：SELECT * FROM users WHERE id=('$id') LIMIT 0,1;SELECT * FROM users WHERE id=('1') and ;-- ') LIMIT 0,1;> err: You have an error in your SQL

数论质数对于一个足够大的NNN, 大约有NlnN\frac{N}{lnN}lnNN​个不超过NNN的质数埃氏筛基本思想:对于整数xxx,任意xxx的倍数都不是质数.复杂度: O(∑质数p≤NNp)=O(Nlog⁡log⁡N)O\left(\sum_{质数p \le N\frac{N}{p}}\right) = O(N\log \log N)O(∑质数p≤NpN​​)=O(NloglogN)for (int i = 2; i <= n; i++) { if (vis[i]) cont