Coloring Trees Problem 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 with integers from 1 to n fr…

C. Coloring Trees 题目连接: http://www.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…

C. Coloring Trees   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 with integers from 1 to n from left to right…

C. Coloring Trees time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon has arrived at Udayland! They walked in the park where n trees grow. They decided to be…

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…

题目:https://codeforces.com/problemset/problem/711/C 题意:给你n,m,k,代表n个数的序列,有m种颜色可以涂,0代表未涂颜色,其他代表已经涂好了,连着一段是相同颜色的是一个连通块,求正好有k个连通块的最小花费 思路:首先每个位置有可能有m中颜色,而且要满足k个,我们我们可以推出所有情况 dp[n][m][k] n代表前n个数 m代表当前涂m色 k代表满足k个了 #include<cstdio> #include<cmath> #in…

题目大意:有n个点,由m种颜料,有些点没有涂色,有些点已经涂色了,告诉你每个点涂m种颜色的价格分别是多少, 让你求将这n个点分成k段最少需要多少钱. 思路:动态规划,我们另dp[ i ][ j ][ k ] 表示到i个点为止,分成j段,最后一段的颜色为k的最少值,然后就能很容易地 写出状态转移方程. #include<bits/stdc++.h> #define ll long long using namespace std; ; const ll inf=0x3f3f3f3f3f3f3f3…

C. Coloring Trees time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon has arrived at Udayland! They walked in the park where ntrees grow. They decided to be n…

http://codeforces.com/group/1EzrFFyOc0/contest/711/problem/C https://blog.csdn.net/qq_36368339/article/details/78568585?locationNum=6&fps=1  题解 题意:(真难理解)有n个点,m种颜色,你要给n个点上没有颜色的点染色.每个点i对应染的颜色j有一个颜料消耗,p[i][j]是点i染成j颜色的花费,你必须保证有k段颜色的点,输出最少花费多少颜料. 思路:题意稍微不…

题目链接: http://codeforces.com/problemset/problem/149/D D. Coloring Brackets time limit per test2 secondsmemory limit per test256 megabytes 问题描述 Once Petya read a problem about a bracket sequence. He gave it much thought but didn't find a solution. Toda…

E. ZS and The Birthday Paradox 题目连接: http://www.codeforces.com/contest/711/problem/E Description ZS the Coder has recently found an interesting concept called the Birthday Paradox. It states that given a random set of 23 people, there is around 50% c…

D. Directed Roads 题目连接: http://www.codeforces.com/contest/711/problem/D Description ZS the Coder and Chris the Baboon has explored Udayland for quite some time. They realize that it consists of n towns numbered from 1 to n. There are n directed roads…

B. Chris and Magic Square 题目连接: http://www.codeforces.com/contest/711/problem/B Description ZS the Coder and Chris the Baboon arrived at the entrance of Udayland. There is a n × n magic grid on the entrance which is filled with integers. Chris notice…

A. Bus to Udayland 题目连接: http://www.codeforces.com/contest/711/problem/A Description ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The IOI bus has n rows of seats. There are 4 sea…

题目链接:http://codeforces.com/problemset/problem/711/D D. Directed Roads time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon has explored Udayland for quite some…

题目链接:https://vjudge.net/problem/CodeForces-149D D. Coloring Brackets time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Once Petya read a problem about a bracket sequence. He gave it much tho…

Bus to Udayland 题目链接: http://codeforces.com/contest/711/problem/A Description ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The IOI bus has n rows of seats. There are 4 seats in e…

Chris and Magic Square 题目链接: http://codeforces.com/contest/711/problem/B Description ZS the Coder and Chris the Baboon arrived at the entrance of Udayland. There is a n × n magic grid on the entrance which is filled with integers. Chris noticed that…

(easy version): 题目链接:http://codeforces.com/contest/1296/problem/E1 题目一句话就是说,两种颜色不同的字符可以相互换位, 问,对这字符串用最多两种颜色染色,然后经过有限次换位 可以变成字典序排序的顺序. 思路:一个字符需不需要换位,应该是参照最后的字典序的顺序, 那么,我们应该给字符串排序,再去思考问题. 我们知道,如果str[now_i]的位置和排序后的位置不一样,那就是需要换位. 我们还知道,如果str[now_i]的当前位置如…

A:=w= B:=w= C:题意:有一排树,有的树已经上色,有的树没有上色,只能给没上色的树上色,一共m种颜色,不同的树上不同的色花费不同,涂完色后,连续颜色的树成为一段.对于给定的段数k,求出最小花费 分析:不是贪心就是dp,这很显然不是贪心 f[i][j][k]表示前i个树,第i个树涂色是j,已经有k段树的最小花费 如果第i个树未染色:f[i][j][k]=min(f[i-1][j][k]+v[i][j],f[i-1][j'][k-1]+v[i][j']) 如果已经染色:f[i][j][k]…

D. Directed Roads   ZS the Coder and Chris the Baboon has explored Udayland for quite some time. They realize that it consists of n towns numbered from 1to n. There are n directed roads in the Udayland. i-th of them goes from town i to some other tow…

A. Bus to Udayland time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The…

D. Directed Roads time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon has explored Udayland for quite some time. They realize that it consists of ntowns numbe…

题目大意:给你n个点n条边的有向图,你可以任意地反转一条边的方向,也可以一条都不反转,问你有多少种反转的方法 使图中没有环. 思路:我们先把有向边全部变成无向边,每个连通图中肯定有且只有一个环,如果这个连通图里边有n个点,环由m个元素 构成,那么这个连通图的反转方法数为,(2^(n-m)) * (2^m-2),然后将所有连通图的种数乘到一起就好啦.具体求圆环由几 个点组成看代码. ps:最后算ans的时候忘了加括号,debug了一个小时QAQ. #include<bits/stdc++.h>…

A. Bus to Udayland time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The…

A:模拟水题不说 #include <iostream> #include <string.h> #include <algorithm> #include <stdio.h> #include <math.h> #include <bitset> using namespace std; typedef long long LL; ; ]; int main(){ int n; scanf("%d",&n…

You are given a tree (a connected undirected graph without cycles) of …

ZS and The Birthday Paradox 题目:一年有2^n天,有k个人,他们的生日有冲突的概率是多少?答案用最简分数表示,分子分母对1e6+3取模.1 ≤ n ≤ 10^18, 2 ≤ k ≤ 10^18. 答案为 1 - A(2^n,k) / (2^n)^k,分子与分母的gcd必定为2^i.计算A(2^n,k)=(2^n) * (2^n-1) * ... * (2^n-k+1)含多少个因子2,相当于计算0~k-1中总共有多少个因子2. 因为分子乘以了模mod后就永远是0了,所以…

Codeforces Round #453 (Div. 1) A. Hashing Trees 题目描述:给出一棵树的高度和每一层的节点数,问是否有两棵树都满足这个条件,若有,则输出这两棵树,否则输出perfect solution 首先判断什么时候是perfect:当不存在相邻两层的节点数均大于\(0\)时,输出perfect. 接下来就是构造的问题.若上一层只有一个节点,那么这一层的所有节点只能连到那个唯一的节点,否则分为两棵树不同的构造: 所有点都连到上一层的第一个节点 第一个点连到上一层…

Codeforces Round #177 (Div. 1) A. Polo the Penguin and Strings 题意 让你构造一个长度为n的串,且里面恰好包含k个不同字符,让你构造的字符串字典序最小. 题解 先abababab,然后再把k个不同字符输出,那么这样就是最少 代码 #include<bits/stdc++.h> using namespace std; string s; int main() { int n,k; scanf("%d%d",&am…