【Codeforces Round #519】 A:https://www.cnblogs.com/myx12345/p/9872082.html B:https://www.cnblogs.com/myx12345/p/9872124.html C:https://www.cnblogs.com/myx12345/p/9872262.html D:https://www.cnblogs.com/myx12345/p/9872409.html E: F: G: