USACOAgriNet

来源：http://ace.delos.com/usacoprob2?a=ecro6SKAJN4&S=agrinet

这题明显的最小生成树，说多了都侮辱我的智商了= =

/*
ID:ay27272
PROG:agrinet
LANG:C++
*/

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

#define NN 105
int map[NN][NN]={0};
int dist[NN];
bool f[NN];

int main()
{
    freopen("agrinet.in","r",stdin);
    freopen("agrinet.out","w",stdout);
    int n;
    cin>>n;
    for (int i=1;i<=n;i++)
        for (int j=1;j<=n;j++)
            cin>>map[i][j];

    memset(dist,10,sizeof(dist));
    memset(f,true,sizeof(f));
    int total=0;
    int S=1;
    for (int i=1;i<=n;i++)
        if (map[S][i]!=0)
            dist[i]=map[S][i];

    dist[1]=0;
    f[S]=false;

    int min,h;
    for (int i=2;i<=n;i++)
    {
        min=dist[0];
        for (int j=1;j<=n;j++)
            if (f[j] && dist[j]<min)
                min=dist[h=j];
        f[h]=false;
        total+=min;
        for (int j=1;j<=n;j++)
            if (map[h][j]!=0 && map[h][j]<dist[j])
                dist[j]=map[h][j];
    }
    cout<<total<<endl;
    return 0;
}