POJ1258-Agri-Net

转载请注明出处：優YoU http://user.qzone.qq.com/289065406/blog/1299324000

提示：又是一题求最小生成树的总权值，继续Prim....

 

 1 //Memory Time 
 2 //300K   32MS 
 3 
 4 #include<iostream>
 5 using namespace std;
 6 
 7 const int inf=100001;      //无限大
 8 
 9 int n;   //农场数量
10 int dist[101][101];
11 
12 int prim(void)
13 {
14     int s=1;
15     int m=1;
16     bool u[101]={false};
17     u[s]=true;
18 
19     int min_w;
20     int prim_w=0;
21     int point;
22     int low_dis[101];
23 
24     /*Initial*/
25 
26     for(int i=1;i<=n;i++)
27         low_dis[i]=inf;
28 
29     /*Prim Algorithm*/
30 
31     while(true)
32     {
33         if(m==n)
34             break;
35 
36         min_w=inf;
37         for(int i=2;i<=n;i++)
38         {
39             if(!u[i] && low_dis[i]>dist[s][i])
40                 low_dis[i] = dist[s][i];
41             if(!u[i] && min_w>low_dis[i])
42             {
43                 min_w = low_dis[i];
44                 point=i;
45             }
46         }
47         s=point;
48         u[s]=true;
49         prim_w+=min_w;
50         m++;
51     }
52     return prim_w;
53 }
54 
55 int main(void)
56 {
57     while(cin>>n)
58     {
59         /*Input*/
60 
61         for(int i=1;i<=n;i++)
62             for(int j=1;j<=n;j++)
63                 cin>>dist[i][j];
64 
65         /*Prim Algorithm & Output*/
66 
67         cout<<prim()<<endl;
68     }
69     return 0;
70 }