143. Long Live the Queen 树形dp 难度:0】的更多相关文章

143. Long Live the Queen time limit per test: 0.25 sec. memory limit per test: 4096 KB The Queen of Byteland is very loved by her people. In order to show her their love, the Bytelanders have decided to conquer a new country which will be named accor…
题目 https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1903 题意 一棵树,根上有VOD站,要求任意叶节点到VOD站的距离不超过k,问最少建新VOD站数. 思路 1. 令vod[i]为节点i到VOD站的最短距离,  注意,这是在以i为根的树上有VOD站的情况下,如果没有,vod[i]就设为非法. 依据树形DP的思路,如果在该…
题目 https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1800 题意 n(n < 1000)个节点m条边的无向无环无重边图,最小顶点覆盖的同时要尽量让只有一个端点是点亮的边数最少 思路 如刘书: 1. 无向无环图一定是森林,适用树形DP 2. 因为有两个优化目标,所以将两个目标线性组合,设以i为根的树上的顶点覆盖数为x,单点点亮边数为…
Rebuilding Roads Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 9105   Accepted: 4122 Description The cows have reconstructed Farmer John's farm, with its N barns (1 <= N <= 150, number 1..N) after the terrible earthquake last May. The…
http://acm.hdu.edu.cn/showproblem.php?pid=4035 求步数期望,设E[i]为在编号为i的节点时还需要走的步数,father为dfs树中该节点的父节点,son为dfs树种该节点的子节点的集合,kl[i]为被杀掉的概率,ex[i]为逃出的概率 mv[i]=(1-kl[i]-ex[i])/(1+len(son)) 则明显 E[i]=(E[father]+1)*mv[i]+sigma((E[son]+1)*mv[i])+E[1]*K[i] 未知量是E[i],E[…
The Lost House Time Limit: 3000MS   Memory Limit: 30000K Total Submissions: 2203   Accepted: 906 Description One day a snail climbed up to a big tree and finally came to the end of a branch. What a different feeling to look down from such a high plac…
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…
104. Little shop of flowers time limit per test: 0.25 sec. memory limit per test: 4096 KB PROBLEM You want to arrange the window of your flower shop in a most pleasant way. You have F bunches of flowers, each being of a different kind, and at least a…
D. Bag of mice time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output The dragon and the princess are arguing about what to do on the New Year's Eve. The dragon suggests flying to the mountains t…
http://acm.timus.ru/problem.aspx?space=1&num=1203 按照结束时间为主,开始时间为辅排序,那么对于任意结束时间t,在此之前结束的任务都已经被处理,从这个时间开始的任务都正要被处理, 因为t<=3e5,可以用简单dp解决 #include <cstdio> #include <algorithm> using namespace std; const int maxn=1e5+5; int n; typedef pair&l…