题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5374 思路:题目的意思是求树上的两点,使得树上其余的点到其中一个点的最长距离最小.可以想到这题与树直径有关,我们可以这样做,首先求出树的直径,然后取出树的中点以及与该中点相邻,并且是直径上的一个点,这样就把这棵树划分为两颗子树,然后分别求出这两棵树的直径,最后要选择的两个点分别就是这两棵树的直径上的中点. 一开始是用dfs写的,结果爆栈了,改成bfs就过了. #in…

套公式 Sample Input 33 bit25 25 50 //百分数7 nat1 2 4 8 16 32 3710 dit10 10 10 10 10 10 10 10 10 10Sample Output 1.5000000000001.4808108324651.000000000000 # include <iostream> # include <cstdio> # include <cstring> # include <algorithm>…

题意:给出A班和B班的学生成绩,如果bob(A班的)在B班的话,两个班级的平均分都会涨.求bob成绩可能的最大,最小值. A班成绩平均值(不含BOB)>A班成绩平均值(含BOB) && B班成绩平均值(不含BOB)< B班成绩平均值(含BOB) 化简后得 B班成绩平均值(不含BOB) < X < A班成绩平均值(不含BOB) Sample Input 24 35 5 54 4 36 55 5 4 5 31 3 2 2 1Sample Output 4 42 4 #…

I - Information Entropy Time Limit:2000MS     Memory Limit:65536KB     64bit IO Format:%lld & %llu Submit Status Description Information Theory is one of the most popular courses in Marjar University. In this course, there is an important chapter abo…

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5376 题意:每天往n*m的棋盘上放一颗棋子,求多少天能将棋盘的每行每列都至少有一颗棋子的期望 分析: 我们来分析一波: 讲解一下弱弱的我的解题思路 (1)首先可以想到的是设一个 dp[val]  表示 当前用了val 个旗子距离目标状态还有几天的概率.但是我们可以发现单纯的一个状态val 是不能表示出准确的状态 , 比如说现在只是知道了我使用了多少的旗子,当前不知道有多少行和…

题目链接:http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5373 题目意思: 有两个class:A 和 B,Bob 在 Class A 里面.现在给出 Class A(n-1人) 和 Class B(m人) 所有人的分数,除了Bob,所以Class A 少了一个人.现在需要找出 Bob 最大可能的分数和最少可能的分数,使得他在Class A 里面拉低平均分,而在Class B 里面提高平均分. 由于数据量不大,所以可以暴力枚…

ZOJ 2819 Average Score Time Limit: 2 Sec  Memory Limit: 60 MB 题目连接 http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemId=5373 Description Bob is a freshman in Marjar University. He is clever and diligent. However, he is not good at math, especia…

首先赞一下题目, 好题 题意: Marjar University has decided to upgrade the infrastructure of school intranet by using fiber-optic technology. There are N buildings in the school. Each building will be installed with one router. These routers are connected by optic…

题目大意:给出一列取样的几个山的高度点,求山峰有几个? Sample Input 291 3 2 4 6 3 2 3 151 2 3 4 5Sample Output 30 # include <iostream> # include <cstdio> # include <cstring> # include <algorithm> # include <cmath> # define LL long long using namespace…

Description 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 decorative chessboard with N rows and M columns. Every day after work, Edward will place…