[USACO08OCT]Watering Hole 题目大意: Farmer John 有\(n(n\le300)\)个牧场,他希望灌溉他的所有牧场.牧场编号为\(1\sim n\),要灌溉一个牧场有两种方式,一个是直接在这个牧场建设一个小型水库,另一个是从别的牧场向这个牧场引水.在第\(i\)个牧场建立小型水库需要\(W_i\)美元,而从第\(i\)个牧场向第\(j\)个牧场引水需要\(P_{i,j}\)美元.即便牧场\(j\)没有建设小型水库,只要有别的有水的水库向它引水,那它自己也有水,而…

题面:P1550 [USACO08OCT]打井Watering Hole 题解:无 代码: #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #define ll long long using namespace std; ; ,edge_head[maxn]; ll Z,ans; *maxn*maxn]; inline void Add_edge(int f…

P1550 [USACO08OCT]打井Watering Hole   对于自己建水库的情况,新建一个虚拟结点,和其他点的边权即为自建水库的费用 这样问题就转化为一个裸最小生成树问题了. 这里用堆优化prim解决. #include<iostream> #include<cstdio> #include<cstring> #include<cctype> #include<queue> #define re register using name…

P1550 [USACO08OCT]打井Watering Hole 题目背景 John的农场缺水了!!! 题目描述 Farmer John has decided to bring water to his N (1 <= N <= 300) pastures which are conveniently numbered 1..N. He may bring water to a pasture either by building a well in that pasture or con…

P1550 [USACO08OCT]打井Watering Hole 题目背景 John的农场缺水了!!! 题目描述 Farmer John has decided to bring water to his N (1 <= N <= 300) pastures which are conveniently numbered 1..N. He may bring water to a pasture either by building a well in that pasture or con…

描述 Description 农民约翰被选为他们镇的镇长!他其中一个竞选承诺就是在镇上建立起互联网,并连接到所有的农场.当然,他需要你的帮助.约翰已经给他的农场安排了一条高速的网络线路,他想把这条线路共享给其他农场.为了用最小的消费,他想铺设最短的光纤去连接所有的农场.你将得到一份各农场之间连接费用的列表,你必须找出能连接所有农场并所用光纤最短的方案.每两个农场间的距离不会超过100000 输入格式 Input Format 第一行: 农场的个数,N(3<=N<=100). 第二行..结尾:…

题面 题目背景 John的农场缺水了!!! 题目描述 Farmer John has decided to bring water to his N (1 <= N <= 300) pastures which are conveniently numbered 1..N. He may bring water to a pasture either by building a well in that pasture or connecting the pasture via a pipe…

题面(翻译有点问题,最后一句话) 农民John 决定将水引入到他的n(1<=n<=300)个牧场.他准备通过挖若 干井,并在各块田中修筑水道来连通各块田地以供水.在第i 号田中挖一口井需要花费W_i(1<=W_i<=100,000)元.连接i 号田与j 号田需要P_ij (1 <= P_ij <= 100,000 , P_ji=P_ij)元. 请求出农民John 需要为使所有农场都与有水的农场相连或拥有水井所需要的钱数. 题意 有n个点,每个点之间都有边权,但是每个点也…

题目描述 Farmer John has decided to bring water to his N (1 <= N <= 300) pastures which are conveniently numbered 1..N. He may bring water to a pasture either by building a well in that pasture or connecting the pasture via a pipe to another pasture whi…

题目背景 John的农场缺水了!!! 题目描述 Farmer John has decided to bring water to his N (1 <= N <= 300) pastures which are conveniently numbered 1..N. He may bring water to a pasture either by building a well in that pasture or connecting the pasture via a pipe to…