Cow Pedigrees Silviu Ganceanu -- 2003 Farmer John is considering purchasing a new herd of cows. In this new herd, each mother cow gives birth to two children. The relationships among the cows can easily be represented by one or more binary trees with…

nocows解题报告------------------------------------------------------------------------------------------------------------------------------------------------[题目] 给你N个点,生成一棵K层的树,有s种情况.请输出s%9901的值. 要求很简单,每个点只能有0个或2个孩子.[数据范围] 3<=N<200 1<K<100[输入格式]…

P1472 奶牛家谱 Cow Pedigrees 102通过 193提交 题目提供者该用户不存在 标签USACO 难度普及+/提高 提交  讨论  题解 最新讨论 暂时没有讨论 题目描述 农民约翰准备购买一群新奶牛. 在这个新的奶牛群中, 每一个母亲奶牛都生两个小奶牛.这些奶牛间的关系可以用二叉树来表示.这些二叉树总共有N个节点(3 <= N < 200).这些二叉树有如下性质: 每一个节点的度是0或2.度是这个节点的孩子的数目. 树的高度等于K(1 < K < 100).高度是从…

问n个结点深度为k且只有度为2或0的二叉树有多少种. dp[i][j]=dp[lk][ln]*dp[rk][j-1-ln],max(lk,rk)=i-1. http://train.usaco.org/usacoprob2?a=chObWjKZP9z&S=nocows /* TASK:nocows LANG:C++ */ #include<cstdio> #include<cstring> #include<algorithm> using namespace…

OJ:http://www.luogu.org/problem/show?pid=1472 #include<iostream> using namespace std; const int MOD=9901; const int maxn=200+5; const int maxk=100+5; int dp[maxn][maxk]; int v[maxn][maxk]; int N,K; void init(){ for(int i=0;i<maxn;i++) for(int j=0…

一道经典Dp. 定义dp[i][j] 表示由i个节点,j 层高度的累计方法数 状态转移方程为: 用i个点组成深度最多为j的二叉树的方法树等于组成左子树的方法数 乘于组成右子树的方法数再累计. & / \ @ # / \ @ @ 如图中 & 为顶点, @ 为左子树, # 为右子树 需要注意的是,左子树的节点数目同样也为奇数 然后遍历一遍从k = 1 到 i - 2, 考虑上一层所有的左/右子树方法数再作累加 最后输出答案的时候减去上一层累加数即可 /* ID: wushuai2 PROG:…

题目链接 Solution 我DP太菜啦... 考虑到一棵二叉树是由根节点以及左儿子和右儿子构成. 所以答案其实就是 左儿子方案数*右儿子方案数 . 状态定义: \(f[i][j]\) 代表深度为 \(i\) ,节点个数为 \(j\) 的二叉树方案数. 转移方程: 对于每一个状态,节点总数已经确定. 那么枚举一维左子树的节点个数,右边用总数减去. 如果要构建一棵深度为 \(i\) 的二叉树,则两棵子树中必有一棵深度为 \(i-1\) . 此时有三种情况: 左子树深度小于 \(i-1\),右子树深…

Cow XORAdrian Vladu -- 2005 Farmer John is stuck with another problem while feeding his cows. All of his N (1 ≤ N ≤ 100,000) cows (numbered 1..N) are lined up in front of the barn, sorted by their rank in their social hierarchy. Cow #1 has the highes…

2590: [Usaco2012 Feb]Cow Coupons Time Limit: 10 Sec Memory Limit: 128 MB Submit: 349 Solved: 181 [Submit][Status][Discuss] Description Farmer John needs new cows! There are N cows for sale (1 <= N <= 50,000), and FJ has to spend no more than his bud…

Cow Tours Farmer John has a number of pastures on his farm. Cow paths connect some pastures with certain other pastures, forming a field. But, at the present time, you can find at least two pastures that cannot be connected by any sequence of cow pat…