Farmer John希望把水源引入他的N (1 <= N <= 300) 个牧场,牧场的编号是1~N.他将水源引入某个牧场的方法有两个,一个是在牧场中打一口井,另一个是将这个牧场与另一个已经有水源的牧场用一根管道相连.在牧场i中打井的费用是W_i (1 <= W_i <= 100000).把牧场i和j用一根管道相连的费用是P_ij (1 <= P_ij <= 100000, P_ij = P_ji, P_ii = 0).请你求出Farmer John最少要花多少钱才能…

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…

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: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…

[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…

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…

397. [USACO Oct09] 热浪 ★☆   输入文件:heatwvx.in   输出文件:heatwvx.out   简单对比时间限制:1 s   内存限制:128 MB 德克薩斯純樸的民眾們這個夏天正在遭受巨大的熱浪!!!他們的德克薩斯長角牛吃起來不錯,可是他們並不是很擅長生產富含奶油的乳製品.Farmer John此時以先天下之憂而憂,後天下之樂而樂的精神,身先士卒地承擔起向德克薩斯運送大量的營養冰涼的牛奶的重任,以減輕德克薩斯人忍受酷暑的痛苦. FJ已經研究過可以把牛奶從威斯康星…

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…