POJ 3662 Telephone Lines (二分+dijkstra)】的更多相关文章

题意 Farmer John想从电话公司修一些电缆连接到他农场.已知N个电线杆编号为1,2,⋯N,其中1号已经连接电话公司,N号为农场,有P对电线杆可连接. 现给出P对电线杆距离Ai,Bi,Li表示Ai和Bi可连接,需要长度为Li的电缆. 电话公司赞助FJ K条免费电缆,额外的支出为剩下所需电缆的最大长度.求出最小费用. 思路 设mid为某条线的长度,长于mid的线放到免费额度里,否则自己掏钱.如果存在一个临界值x,使得长于x的电线数量恰好等于K,这个临界值对应的解就是最优解.如何计算长于mid…
题意: 多年以后,笨笨长大了,成为了电话线布置师.由于地震使得某市的电话线全部损坏,笨笨是负责接到震中市的负责人. 该市周围分布着N(1<=N<=1000)根据1……n顺序编号的废弃的电话线杆,任意两根线杆之间没有电话线连接,一共有p(1<=p<=10000)对电话杆可以拉电话线. 其他的由于地震使得无法连接. 第i对电线杆的两个端点分别是ai,bi,它们的距离为li(1<=li<=1000000).数据中每对(ai,bi)只出现一次.编号为1的电话杆已经接入了全国的电…
Telephone Lines Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7214   Accepted: 2638 Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of…
查看题目 最小化第K大值. 让我怀疑人生的一题目,我有这么笨? #include <cstdio> #include <queue> #include <cstring> #include <vector> #include <functional> using namespace std; #define maxv 1010 #define maxl 1000000 struct edge { int to, cost; edge(){} ed…
题目链接:http://poj.org/problem?id=3662 Telephone Lines Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 8248   Accepted: 2977 Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncoopera…
Telephone Lines Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6973   Accepted: 2554 Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of…
Telephone Lines Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 5696   Accepted: 2071 Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of…
Telephone Lines Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7115   Accepted: 2603 Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of…
意甲冠军: 到n节点无向图,它要求从一个线1至n路径.你可以让他们在k无条,的最大值.如今要求花费的最小值. 思路: 这道题能够首先想到二分枚举路径上的最大值,我认为用spfa更简洁一些.spfa的本质是一种搜索算法,既然是搜索,就涉及到状态的转移. 在一般求最短路的spfa算法中,当到结点u时,对e(u,v)仅仅需做例如以下转移:if(d[v]>d[u]+w(e)) d[v]=d[u]+w(e).在跟一般的情况下.到结点u,对e(u,v)需做多种转移.比方这题中要考虑让e免费和不让e免费两种情…
Telephone Lines Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 6785   Accepted: 2498 Description Farmer John wants to set up a telephone line at his farm. Unfortunately, the phone company is uncooperative, so he needs to pay for some of…