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…

3799567 2014-10-14 10:13:59                                                                     Accepted                                                             3822 C++ 1870 71760 njczy2010 3799566 2014-10-14 10:13:25                            …

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…

Description Do you know reverse Polish notation (RPN)? It is a known notation in the area of mathematics and computer science. It is also known as postfix notation since every operator in an expression follows all of its operands. Bob is a student in…

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 #…

The 2014 ACM-ICPC Asia Mudanjiang Regional Contest 题目链接 没去现场.做的网络同步赛.感觉还能够,搞了6题 A:这是签到题,对于A堆除掉.假设没剩余在减一.B堆直接除掉 + 1就能够了 B:二分贪心,二分长度.然后会发现本质上是在树上最长链上找两点,那么有二分出来的长度了,就从两端分别往里移动那么长,那两个位置就是放置位置.然后在推断一下就能够了 D:概率DP.首先知道放一个棋子.能够等价移动到右上角区域,那么就能够dp[x][y][k],表示…

Domination Time Limit: 8 Seconds      Memory Limit: 131072 KB      Special Judge 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 chessboar…

题目链接:ZOJ 3827 Information Entropy 依据题目的公式算吧,那个极限是0 AC代码: #include <stdio.h> #include <string.h> #include <math.h> const double e=exp(1.0); double find(char op[]) { if(op[0]=='b') return 2.0; else if(op[0]=='n') return e; else if(op[0]=='…