04 2019 档案

Codeforces Round #553 F Sonya and Informatics
摘要："题目" 题目大意 给定一个长为 $n$（$2 \le n \le 100$）的01串 $S$ 。对 $S$ 进行 $k$（$1 \le k \le 10^9$）次操作：等概率地选取两个下标 $i, j$（$1 \le i 阅读全文
posted @ 2019-04-19 03:26 Pat 阅读(333) 评论(0) 推荐(0)
shared_ptr 的循环依赖问题
摘要：```c++ include include using namespace std; struct A; struct B; struct A { shared_ptr B_ptr; A() { cout A_ptr; B() { cout ap(new A()); // ap 的引用计数是1 s 阅读全文
posted @ 2019-04-08 23:41 Pat 阅读(694) 评论(2) 推荐(0)
【C++ 拾遗】extern 关键字
摘要：Separate compilation let us split our programs into several files, each of which can be compiled independently. allows programs to be written in logic 阅读全文
posted @ 2019-04-08 23:37 Pat 阅读(354) 评论(0) 推荐(0)