(以下修改指1和2类操作,询问指3类操作,操作指修改或询问) 注意到总方案数确定,那么不妨求出答案的期望,再乘上方案数即为答案 (这里从期望的角度考虑只是为了描述方便,并没有太大的实际意义) 设$E(t)$为对某一个位置执行$t$次修改(指对该点)后该位置的期望,通过概率去求,即设$P(t,i)$表示经过$t$次修改后为$i$的概率,那么$E(t)=\sum_{i=0}^{m-1}i\cdot P(t,i)$ 初始有$P(0,0)=1$,接下来有$P(t,i)=\frac{\sum_{j=0}^…

Argestes and Sequence Time Limit: 5000/2500 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 566    Accepted Submission(s): 142 Problem Description Argestes has a lot of hobbies and likes solving query problems espec…

Time Limit: / MS (Java/Others) Memory Limit: / K (Java/Others) Total Submission(s): Accepted Submission(s): Problem Description Argestes has a lot of hobbies and likes solving query problems especially. One day Argestes came up with such a problem. Y…

D. Serega and Fun Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/455/problem/D Description Serega loves fun. However, everyone has fun in the unique manner. Serega has fun by solving query problems. One day Fedor came up w…

reference:http://java.dzone.com/articles/caching-best-practices There is an irresistible attraction to writing custom caching solutions, since it seems to be the easiest path to “improving” the overall application performance. Well, caching is a grea…

Argestes and Sequence Time Limit: 5000/2500 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 511    Accepted Submission(s): 127 Problem Description Argestes has a lot of hobbies and likes solving query problems espec…

HDOJ5054 Alice and Bob Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 302    Accepted Submission(s): 229 Problem Description Bob and Alice got separated in the Square, they agreed that if they…

Argestes and Sequence Time Limit: 5000/2500 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1279    Accepted Submission(s): 373 Problem Description Argestes has a lot of hobbies and likes solving query problems espec…

Serega loves fun. However, everyone has fun in the unique manner. Serega has fun by solving query problems. One day Fedor came up with such a problem. You are given an array a consisting of n positive integers and queries to it. The queries can be of…

Graph Fundamentals 基础 Basic concepts to get you going. A graph database can store any kind of data using a few simple concepts: Nodes - graph data records 节点 Relationships - connect nodes 关系 Properties - named data values 属性   A Graph Database Neo4j…