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…

题目大意 有N个节点以及连接的P个无向边,现在要通过这P条边从1号节点连接到N号节点.若无法连接成功,则返回-1:若能够连接成功,那么其中用到了L条边,这L条边中有K条边可以免费,L-K条边不能免费,求出不能免费的边的最大长度. 题目分析 判断能否到达,可以通过BFS搜索路径,若不能到达,返回-1:若能到达,且最少需要的路径的边数小于等于K,那么所有的边都可以免费,则返回0:若能够到达,且最少需要的路径边数大于K,则需要求出从节点1到节点N的路径中第K+1长的边的最小值,即最小化第k大的值问题.…

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…

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…

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: 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: 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: 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…

POJ 3273 Monthly Expense二分查找(最大值最小化问题) 题目:Monthly Expense Description Farmer John is an astounding accounting wizard and has realized he might run out of money to run the farm. He has already calculated and recorded the exact amount of money (1 ≤ mon…