题目 P4271 [USACO18FEB]New Barns 做法 这题很长见识啊!! 知识点:两棵树\((A,B)\)联通后,新树的径端点为\(A\)的径端点与\(B\)的径端点的两点 不断加边,那就\(LCT\)维护联通块径端点就好了,两点的简单路径就是把链拉起来的子树 My complete code #include<cstdio> #include<iostream> #include<cstring> #include<string> #incl…

New Barns 时间限制: 1 Sec  内存限制: 128 MB 题目描述 Farmer John notices that his cows tend to get into arguments if they are packed too closely together, so he wants to open a series of new barns to help spread them out. Whenever FJ constructs a new barn, he co…

浅谈一下对于这题做完之后的感受(不看题解也是敲不出来啊qwq--) 题意翻译 Farmer John注意到他的奶牛们如果被关得太紧就容易吵架,所以他想开放一些新的牛棚来分散她们. 每当FJ建造一个新牛棚的时候,他会将这个牛棚用至多一条双向道路与一个现有的牛棚连接起来.为了确保他的奶牛们足够分散,他有时想要确定从某个特定的牛棚出发,到它能够到达的最远的牛棚的距离(两个牛棚之间的距离等于从一个牛棚出发到另一个之间必须经过的道路条数). FJ总共会给出QQ(1 \leq Q \leq 10^51≤Q≤…

题意 每次新建一个节点,并与一个已知节点连边.(或者不连).多次询问以某个已知点点出发的最远路径长度. 分析 显然,在任何时候图都是一个森林.由树的直径算法可知,与某点最远距的点必然是树的直径的一段.那么考虑在lct中维护直径. 实现 一篇精彩的LCT,应该像少女穿的迷你裙,越短越好.--林语堂 (误 #include <bits/stdc++.h> using namespace std; const int N=1e5+10; namespace lct { int ch[N][2],fa…

[题目链接] https://www.lydsy.com/JudgeOnline/problem.php?id=5192 [算法] 维护树的直径,在树上离一个点最远的点一定是一条直径的端点.         在直径为(x , y)的树上加入一个叶子结点z,则新的直径必然为(x , y) , (x , z) , (y , z)中的一条 , 问题转化为询问树上两点距离 , 倍增即可 , 时间复杂度 :O(MlogN) [代码] #include<bits/stdc++.h> using names…

不想写看zory大佬 #include<cstdio> #include<iostream> #include<cstring> #include<cstdlib> #include<algorithm> #include<cmath> using namespace std; ]; ][],Bin[]; int LCA(int x,int y) { if(dep[x]<dep[y])swap(x,y); ;i>=;i--…

题意 给一个一开始没有点的图,有 \(q\) 次操作,每次为加点连边或者查询一个点到连通块内所有点的距离最大值. \(\texttt{Data Range}:1\leq q\leq 10^5\) 题解 跟「雅礼集训 2017 Day5」远行很像的一个题,都是 LCT 维护直径. 注意到树上一个点到其他点的距离最大值只可能在直径的两个端点处取到,而且又存在加边操作,所以可以直接使用 LCT 来维护. 当合并两个连通块的时候需要在两个连通块各自的直径端点中选两个成为新的直径,需要讨论 \(6\) 种…

Rebuilding Roads Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 11495   Accepted: 5276 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. Th…

在很多时候,并查集并不是一个完整的解题方法,而是一种思路. 通过以下题目来体会并查集逆向运用的思想. Description Farmer John and his cows are planning to leave town for a long vacation, and so FJ wants to temporarily close down his farm to save money in the meantime.The farm consists of NN barns con…

3697: 采药人的路径 Time Limit: 10 Sec  Memory Limit: 128 MBSubmit: 681  Solved: 246[Submit][Status][Discuss] Description 采药人的药田是一个树状结构,每条路径上都种植着同种药材.采药人以自己对药材独到的见解,对每种药材进行了分类.大致分为两类,一种是阴性的,一种是阳性的.采药人每天都要进行采药活动.他选择的路径是很有讲究的,他认为阴阳平衡是很重要的,所以他走的一定是两种药材数目相等的路径.…

树形DP..... Rebuilding Roads Time Limit: 1000MS Memory Limit: 30000K Total Submissions: 8188 Accepted: 3659 Description The cows have reconstructed Farmer John's farm, with its N barns (1 <= N <= 150, number 1..N) after the terrible earthquake last Ma…

Rebuilding Roads   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 cows didn't have time to rebuild any extra roads, so now there is exactly one wa…

Rebuilding RoadsTime Limit: 1000MS Memory Limit: 30000KTotal Submissions: 8589 Accepted: 3854Description 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 cows d…

Fiber Communications Time Limit: 1000MS   Memory Limit: 30000K Total Submissions: 3804   Accepted: 1160 Description Farmer John wants to connect his N (1 <= N <= 1,000) barns (numbered 1..N) with a new fiber-optic network. However, the barns are loc…

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 cows didn't have time to rebuild any extra roads, so now there is exactly one way to get from any g…

    A-L 二分匹配 M-O 二分图多重匹配 P-Q 二分图最大权匹配 R-S 一般图匹配带花树 模板请自己找     ID Origin Title   61 / 72 Problem A HDU 1045 Fire Net   52 / 112 Problem B HDU 2444 The Accomodation of Students   45 / 86 Problem C HDU 1083 Courses   44 / 63 Problem D HDU 1281 棋盘游戏   35…

题目连接 http://poj.org/problem?id=2377 Bad Cowtractors Description Bessie has been hired to build a cheap internet network among Farmer John's N (2 <= N <= 1,000) barns that are conveniently numbered 1..N. FJ has already done some surveying, and found…

Building roads Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6091   Accepted: 2046 Description Farmer John's farm has N barns, and there are some cows that live in each barn. The cows like to drop around, so John wants to build some ro…

The Sorrows of Young Werther J.W. von Goethe Thomas Carlyle and R.D. Boylan Edited by Nathen HaskellDole PREFACE I have carefully collected whatever I have been able to learnof the story of poor Werther, and here present it to you , knowing thatyou w…

题意 此题题意不太好懂.现有n头牛和b个牛棚,每个牛棚可以养的牛的数目都有一个限制c[i],表示该牛棚最多只能关c[i]头牛,每头牛对每一个牛棚都有一个喜爱值,用1到b来表示,现在要安排这些牛,使得牛棚中的牛对牛棚的最大喜爱值与最小喜爱值的差值最小. 分析: 枚举区间+最大流 新建源点向每头牛连边 牛向barns连边 barns向汇点连边,边权为barns的容量,其实就是一个二分图 最后求最大流就好了 // File Name: 3189.cpp // Author: Zlbing // Cre…

#瓦登尔湖词频统计: import string path = 'D:/python3/Walden.txt' with open(path,'r',encoding= 'utf-8') as text: words = [raw_word.strip(string.punctuation).lower() for raw_word in text.read().split()] words_index = set(words) counts_dict = {index:words.count(…

Building roads Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 6229   Accepted: 2093 Description Farmer John's farm has N barns, and there are some cows that live in each barn. The cows like to drop around, so John wants to build some ro…

Description Farmer Johnson's Bulls love playing basketball very much. But none of them would like to play basketball with the other bulls because they believe that the others are all very weak. Farmer Johnson has N cows (we number the cows from 1 to…

C - 树形dp Crawling in process... Crawling failed Time Limit:1000MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Description After Farmer John realized that Bessie had installed a "tree-shaped" network among his N (…

Description Bessie has been hired to build a cheap internet network among Farmer John's N (2 <= N <= 1,000) barns that are conveniently numbered 1..N. FJ has already done some surveying, and found M (1 <= M <= 20,000) possible connection route…

上一章我们说到,智能手机 == 电脑 + 移动网卡,这个提法比较粗略,更精准的提法应当是,智能手机的硬件结构分为应用程序处理器AP,和基带处理器BP两个部分.虽然AP部分的功能与电脑主板基本类似,但是硬件结构有很大不同,不同之处体现在CPU的选择,以及整个主板的布局连线. BP负责所有通讯软件的执行,它的硬件结构,也并非如网卡那么简单.基带处理器BP的实现,有三种方式. 1. 分立器件(Discrete Components). 把BP部分的CPU,内存,电源管理,无线收发器,功率放大器等等器件…

解题报告 http://blog.csdn.net/juncoder/article/details/38340447 题目传送门 题意: B个猪圈,N头猪.每头猪对每一个猪圈有一个惬意值.要求安排这些猪使得最大惬意和最小惬意的猪差值最小 思路: 二分图的多重匹配问题; 猪圈和源点连边,容量为猪圈容量.猪与汇点连边,容量1; 猪圈和猪之间连线取决所取的惬意值范围; 二分查找惬意值最小差值的范围. #include <iostream> #include <cstring> #inc…

Description Farmer John wants to connect his N (1 <= N <= 1,000) barns (numbered 1..N) with a new fiber-optic network. However, the barns are located in a circle around the edge of a large pond, so he can only connect pairs of adjacent barns. The ci…

Building roads Time Limit: 10000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 34 Accepted Submission(s): 13   Problem Description Farmer John's farm has N barns, and there are some cows that live in each barn.…

题链:http://poj.org/problem? id=3168 Barn Expansion Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 2087   Accepted: 544 Description Farmer John has N (1 <= N <= 25,000) rectangular barns on his farm, all with sides parallel to the X and…