摘要:
找一个值 int find(const int &val, const std::vector<int> &data) { int l = 0, r = data.size(); while(l < r) { int mid = (l + r) >> 1; if (data[mid] == val) 阅读全文
摘要:
Groups Laws of Composition 1.1 For all $a,b,c\in S$, we have $(ab)c = a = a(bc)$, therefore law of composition in $S$ is associative. Suppose $e$ is t 阅读全文