Agri-Net

poj1258:http://poj.org/problem?id=1258

题意：生成树的模板题。简单题。

 #include<iostream>
 #include<cstring>
 #include<cstdio>
 #include<algorithm>
 #define INF 100000000
 #define MAXN 103
 using namespace std;
 int n,m;
 int Edge[MAXN][MAXN];
 int lowcost[MAXN];
 int nearvex[MAXN];
 void prim(int u0){
     int i,j;
     int sumweight=;
     for( i=;i<=n;i++){
         lowcost[i]=Edge[u0][i];
         nearvex[i]=u0;
     }
     nearvex[u0]=-;
     for( i=;i<n;i++){
         int min=INF;
         int v=-;
         for(j=;j<=n;j++){
             if(nearvex[j]!=-&&lowcost[j]<min){
                 v=j;min=lowcost[j];
             }
         }
         if(v!=-){
             nearvex[v]=-;
             sumweight+=lowcost[v];
             for(j=;j<=n;j++){
                 if(nearvex[j]!=-&&Edge[v][j]<lowcost[j]){
                     lowcost[j]=Edge[v][j];
                     nearvex[j]=v;

                 }
             }
         }
     }
     printf("%d\n",sumweight);
 }
 int main(){
     int i,j;
     int u,v,w;
     while(~scanf("%d",&n)){
     memset(Edge,,sizeof(Edge));
     for(i=;i<=n;i++){
         for(j=;j<=n;j++){
           scanf("%d",&w);
           Edge[i][j]=Edge[j][i]=w;
         }
     }
     for( i=;i<=n;i++)
       for( j=;j<=n;j++){
           if(i==j)Edge[i][j]=;
           else if(Edge[i][j]==)Edge[i][j]=INF;
       }
       prim();
 }
 }