D. Birthday 题目连接: http://www.codeforces.com/contest/623/problem/D Description A MIPT student named Misha has a birthday today, and he decided to celebrate it in his country house in suburban Moscow. n friends came by, and after a typical party they d…

D. Array GCD 题目连接: http://codeforces.com/contest/624/problem/D Description You are given array ai of length n. You may consecutively apply two operations to this array: remove some subsegment (continuous subsequence) of length m < n and pay for it m·…

C. Graph and String 题目连接: http://codeforces.com/contest/624/problem/C Description One day student Vasya was sitting on a lecture and mentioned a string s1s2... sn, consisting of letters "a", "b" and "c" that was written on hi…

B. Making a String 题目连接: http://codeforces.com/contest/624/problem/B Description You are given an alphabet consisting of n letters, your task is to make a string of the maximum possible length so that the following conditions are satisfied: the i-th…

A. Save Luke 题目连接: http://codeforces.com/contest/624/problem/A Description Luke Skywalker got locked up in a rubbish shredder between two presses. R2D2 is already working on his rescue, but Luke needs to stay alive as long as possible. For simplicity…

这是我第一次完整地参加codeforces的比赛! 成绩 news standings中第50. 我觉这个成绩不太好.我前半小时就过了前三题,但后面的两题不难,却乱搞了1.5h都没有什么结果,然后在等System test的时候,就有点头绪了,囧.肯定是我在比赛的时候太困了(这是借口吗?). A Save Luke 考你会不会编程. B Making a String 贪心即可.这题是Hack最多的题.幸好我没有被. C Graph and String 注意到,如果某两个点之间没有边,说明其中…

B. Making a String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You are given an alphabet consisting of n letters, your task is to make a string of the maximum possible length so that th…

A. Save Luke time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Luke Skywalker got locked up in a rubbish shredder between two presses. R2D2 is already working on his rescue, but Luke needs to…

C. Electric Charges 题目连接: http://www.codeforces.com/contest/623/problem/C Description Programmer Sasha is a student at MIPT (Moscow Institute of Physics and Technology) and he needs to make a laboratory work to pass his finals. A laboratory unit is a…

C. Graph and String time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output One day student Vasya was sitting on a lecture and mentioned a string s1s2... sn, consisting of letters "a", "…