题目地址:CF1139C Edgy Trees 红黑树 \(ans\) 应该等于总数(\(n^k\))减去不含黑色边的序列数量 不含黑色边就意味着一个序列只能在一个红色联通块中 一个红色联通块中的序列数量应该是点数的 \(k\) 次方 求联通块用dfs用并查集都可以 然后快速幂一下再一减就是 \(ans\) #include <bits/stdc++.h> #define ll long long using namespace std; const int N = 1e5 + 6, P =…
C. Edgy Trees time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given a tree (a connected undirected graph without cycles) of nn vertices. Each of the n−1n−1 edges of the tree is col…
链接 [https://codeforces.com/contest/1139/problem/C] 题意 给你n个点,n-1个边,无向的.有red和black的. k表示经过这k个点.可以跨其他点 分析 先算所有的,再减去不符合即可以了.不符合就是都走0的那种 用dfs求联通块并记录该块有多少个点就可以了,看代码吧 代码 #include<bits/stdc++.h> using namespace std; #define ll long long const int N=2e5+10;…
一.题面 here 二.分析 这题刚开始没读懂题意,后来明白了,原来就是一个数连通块里点数的问题.首先在建图的时候,只考虑红色路径上的点.为什么呢,因为为了不走红色的快,那么我们可以反着想只走红色的路径,这样把所有的可能数再减去只走红色路径的数就是最终的答案了.这里要注意的是,如果连通块里只有一个点,那么就是K个点都是这个点的情况,根据题意是不满足的,也要减去. 三.AC代码 #include<bits/stdc++.h> using namespace std; typedef long l…
http://codeforces.com/contest/1139 A. Even Substrings You are given a string s=s1s2…sns=s1s2…sn of length nn, which only contains digits 11, 22, ..., 99. A substring s[l…r]s[l…r] of ss is a string slsl+1sl+2…srslsl+1sl+2…sr. A substring s[l…r]s[l…r] …
没打,简单补档 C.Edgy Trees 容斥,把黑边断掉数联通块,每个联通块贡献$siz^k$ #include<cstdio> #include<cstring> #include<algorithm> using namespace std; ,mod=1e9+; int n,k,t1,t2,t3,tot,aset[N],siz[N]; int Finda(int x) { return x==aset[x]?x:aset[x]=Finda(aset[x]); }…
For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all possible rooted trees, those with minimum height are called minimum height trees (MHTs). Given such a graph, write…
Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 这道题实际上是Catalan Number卡塔兰数的一个例子,如果对卡塔兰数不熟悉的童鞋可能真…
Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 confused what "{1,#,2…
Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example, Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ …
http://staff.city.ac.uk/~ross/papers/FingerTree.html Summary We present 2-3 finger trees, a functional representation of persistent sequences supporting access to the ends in amortized constant time, and concatenation and splitting in time logarithmi…
Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example, given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 …
Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 Tree Dynamic Programming 如果集合为空,只有一种BST,即空树…
题目链接 http://codeforces.com/contest/711/problem/C Description ZS the Coder and Chris the Baboon has arrived at Udayland! They walked in the park where n trees grow. They decided to be naughty and color the trees in the park. The trees are numbered wit…
Unique Binary Search Trees II Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \…
Get Many Persimmon Trees Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 3243 Accepted: 2113 Description Seiji Hayashi had been a professor of the Nisshinkan Samurai School in the domain of Aizu for a long time in the 18th century. In orde…
Given two Binary Search Trees, find common nodes in them. In other words, find intersection of two BSTs. Example: from: http://www.geeksforgeeks.org/print-common-nodes-in-two-binary-search-trees/ Method 1 (Simple Solution) A simple way is to one by o…
For a undirected graph with tree characteristics, we can choose any node as the root. The result graph is then a rooted tree. Among all possible rooted trees, those with minimum height are called minimum height trees (MHTs). Given such a graph, write…
Unique Binary Search Trees Given n, how many structurally unique BST's (binary search trees) that store values 1...n? For example,Given n = 3, there are a total of 5 unique BST's. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \ 2 1 2 3 推导出递推公式即可: 对于1个元素来…
Unique Binary Search Trees II Given n, generate all structurally unique BST's (binary search trees) that store values 1...n. For example,Given n = 3, your program should return all 5 unique BST's shown below. 1 3 3 2 1 \ / / / \ \ 3 2 1 1 3 2 / / \ \…
