POJ训练计划1258_Agri-Net(最小生成树)
来源:互联网 发布:如何获取域名 编辑:程序博客网 时间:2024/06/11 07:03
Agri-Net
Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 37835 Accepted: 15228
Description
Farmer John has been elected mayor of his town! One of his campaign promises was to bring internet connectivity to all farms in the area. He needs your help, of course.
Farmer John ordered a high speed connection for his farm and is going to share his connectivity with the other farmers. To minimize cost, he wants to lay the minimum amount of optical fiber to connect his farm to all the other farms.
Given a list of how much fiber it takes to connect each pair of farms, you must find the minimum amount of fiber needed to connect them all together. Each farm must connect to some other farm such that a packet can flow from any one farm to any other farm.
The distance between any two farms will not exceed 100,000.
Farmer John ordered a high speed connection for his farm and is going to share his connectivity with the other farmers. To minimize cost, he wants to lay the minimum amount of optical fiber to connect his farm to all the other farms.
Given a list of how much fiber it takes to connect each pair of farms, you must find the minimum amount of fiber needed to connect them all together. Each farm must connect to some other farm such that a packet can flow from any one farm to any other farm.
The distance between any two farms will not exceed 100,000.
Input
The input includes several cases. For each case, the first line contains the number of farms, N (3 <= N <= 100). The following lines contain the N x N conectivity matrix, where each element shows the distance from on farm to another. Logically, they are N lines of N space-separated integers. Physically, they are limited in length to 80 characters, so some lines continue onto others. Of course, the diagonal will be 0, since the distance from farm i to itself is not interesting for this problem.
Output
For each case, output a single integer length that is the sum of the minimum length of fiber required to connect the entire set of farms.
Sample Input
40 4 9 214 0 8 179 8 0 1621 17 16 0
Sample Output
28
Source
USACO 102
解题报告
模板题。
#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#define inf 99999999using namespace std;int mmap[510][510],n;void prim(){ int i,j,dis[510],vis[510],u,mmin,ans=0; for(i=0;i<n;i++) { dis[i]=mmap[0][i]; vis[i]=0; } dis[0]=0; vis[0]=1; for(i=0;i<n-1;i++) { mmin=inf;u=-1; for(j=0;j<n;j++) { if(!vis[j]&&mmin>dis[j]) { mmin=dis[j]; u=j; } } ans+=mmin; vis[u]=1; for(j=0;j<n;j++) { if(!vis[j]&&dis[j]>mmap[u][j]) dis[j]=mmap[u][j]; } } cout<<ans<<endl;}int main(){ int i,j; while(cin>>n) { for(i=0;i<n;i++) for(j=0;j<n;j++) cin>>mmap[i][j]; prim(); } return 0;}
0 0
- POJ训练计划1258_Agri-Net(最小生成树)
- POJ训练计划1789_Truck History(最小生成树)
- POJ训练计划3026_Borg Maze(最小生成树+BFS)
- POJ训练计划2485_Highways(最小生成树)
- POJ 1258 Agri-Net(最小生成树)
- POJ 1258 Agri-Net 【最小生成树】
- Agri-Net - POJ 1258 最小生成树
- POJ 1258 Agri-Net 最小生成树
- POJ 1258 Agri-Net(最小生成树)
- POJ 1258 Agri-Net 最小生成树
- POJ 1258 Agri-Net 最小生成树
- poj 1258 Agri-Net(最小生成树)
- poj 1258 Agri-Net 最小生成树
- Poj 1258 Agri-Net【最小生成树】
- poj 1258 Agri-Net 最小生成树
- POJ 1258Agri-Net 最小生成树
- POJ 1258 :Agri-Net(最小生成树)
- POJ 1258 Agri-Net (最小生成树)
- 手机的通信过程
- 通过设置android:imeOptions来改变软键盘Enter键图标
- 类型相关的定义
- HTMLParser简单应用
- IPtables中SNAT、DNAT和MASQUERADE的含义
- POJ训练计划1258_Agri-Net(最小生成树)
- ip rule 命令
- 错误报告error.h
- ZOJ 3795 Grouping
- MFC编辑框改变背景、颜色等
- rtp
- 查找中的算法----HASH查找,二分查找,堆查找,B树查找,字典树,海量查找
- 字符处理函数ctype.h和wctype.h
- 使用xrand将Centos链接投影仪