摘要：
链接： https://codeforces.com/contest/1278/problem/D 题意： As the name of the task implies, you are asked to do some work with segments and trees. Recall t 阅读全文
摘要：
链接： https://codeforces.com/contest/1278/problem/C 题意： Karlsson has recently discovered a huge stock of berry jam jars in the basement of the house. Mo 阅读全文
摘要：
链接： https://codeforces.com/contest/1278/problem/B 题意： You are given two integers a and b. You can perform a sequence of operations: during the first o 阅读全文
摘要：
链接： https://codeforces.com/contest/1278/problem/A 题意： Polycarp has built his own web service. Being a modern web service it includes login feature. An 阅读全文