海哥天下第一

摘要： 题目链接：http://codeforces.com/contest/934/problem/C 因为最后要找的是一段单调非减区间，所以最后形成的序列一定是11...12....22。中间有一个从1到2的断点。 现在要找一个区间反转，如果反转之后形成的序列的断点不在这个区间内，那么这次反转就没有任何 阅读全文

摘要： Edward is the headmaster of Marjar University. He is enthusiastic about chess and often plays chess with his friends. What's more, he bought a large d 阅读全文

摘要： Problem Description Hzz loves aeroplane chess very much. The chess map contains N+1 grids labeled from 0 to N. Hzz starts at grid 0. For each step he 阅读全文

摘要： Problem Description Akemi Homura is a Mahou Shoujo (Puella Magi/Magical Girl).Homura wants to help her friend Madoka save the world. But because of th 阅读全文

摘要： Description Ivan is fond of collecting. Unlike other people who collect post stamps, coins or other material stuff, he collects software bugs. When Iv 阅读全文

摘要： Description Organizing a programming contest is not an easy job. To avoid making the problems too difficult, the organizer usually expect the contest 阅读全文

摘要： 有2^n个人进行比赛，所以可以推出比赛共需要进行n轮，单独考虑第n轮中序号为i的人需要面对的潜在对手，将这些对手分别考虑。 转移方程为dp[i][j]+=dp[k][j-1]*dp[i][j-1]*a[i][k];即晋级的概率=∑（自己来到这一轮的概率*对手来到这一轮的概率*战胜对手的概率） 阅读全文

摘要： 概率dp入门题，转移方程为dp[i]=dp[i-1]*p+dp[i-2]*(1-p) 因为n个数字上限很大，所以常规的概率dp基本不可能，要用矩阵优化。 把路程分成n+1段，分别计算通过每段的成功率，即刚好跨越地雷的概率（dp[地雷x+1]） 算好每段之后把每段的成功率相乘。 （若有两颗地雷相邻那么 阅读全文

摘要： 矩阵快速幂模板（手撸一遍，一下午修改的头要爆炸了！！！！！！！） 果然是菜原罪╮(╯▽╰)╭ 阅读全文

摘要： Description Imagine you are standing inside a two-dimensional maze composed of square cells which may or may not be filled with rock. You can move nor 阅读全文