zoukankan      html  css  js  c++  java
  • Poj1258--Agri-Net(Prime)

    Agri-Net
    Time Limit: 1000MS   Memory Limit: 10000K
    Total Submissions: 45330   Accepted: 18627

    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.

    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

    4
    0 4 9 21
    4 0 8 17
    9 8 0 16
    21 17 16 0
    

    Sample Output

    28

    Source

     
     1 #include <cstdio>
     2 #include <cstring>
     3 #include <iostream>
     4 using namespace std;
     5 const int INF = 0x3f3f3f3f;
     6 int map[120][120], dis[120], vis[120];
     7 int n;
     8 void Prim()
     9 {
    10     memset(vis, 0, sizeof(vis));
    11     for(int i = 0; i < n; i++)
    12         dis[i] = map[0][i];
    13     vis[0] = 1; int sum = 0;
    14     for(int i = 1; i < n; i++)
    15     {
    16         int min = INF, temp;
    17         for(int j = 0; j < n; j++)
    18         {
    19             if(!vis[j] && dis[j] < min)
    20             {
    21                 temp = j;
    22                 min = dis[j];    
    23             } 
    24         } 
    25         vis[temp] = 1;
    26         sum += min;
    27         for(int j = 0; j < n; j++)
    28             if(!vis[j] && dis[j] > map[temp][j])
    29                 dis[j] = map[temp][j];
    30     }
    31     printf("%d
    ", sum);
    32 }
    33 int main()
    34 {
    35     while(~scanf("%d", &n))
    36     {
    37         for(int i = 0; i < n; i++)
    38             for(int j = 0; j < n; j++)
    39                 cin >> map[i][j];
    40         Prim();
    41     }
    42     return 0;
    43 }
  • 相关阅读:
    【学习小记】一般图最大匹配——带花树算法
    如何检查oracle的归档空间是否满了
    Linux 的计划任务
    转 oracle的热备份和冷备份
    SQLException: Io 异常: Connection refused ERR=12514 ERR=1153异常处理过程
    查看oracle数据库版本
    ORACLE默认实例设置--linux
    oracle查看用户属于哪个表空间
    oracle默认数据库实例
    oracle 查看用户所在的表空间
  • 原文地址:https://www.cnblogs.com/soTired/p/4731230.html
Copyright © 2011-2022 走看看