I

I - Agri-Net

poj 1258

注意：多组数据输入。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define MAXN 110
using namespace std;
int fa[MAXN];
int n,tot,sum,ans;
struct nond{
    int x,y,z;
}v[MAXN*MAXN];
int cmp(nond a,nond b){
    return a.z<b.z;
}
int find(int x){
    if(fa[x]==x)    return x;
    else return fa[x]=find(fa[x]);
}
int main(){
    while(scanf("%d",&n)!=EOF){
        tot=0;ans=0;sum=0;
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++){
                int x;scanf("%d",&x);
                if(i==j)    continue;
                v[++tot].x=i;v[tot].y=j;v[tot].z=x;
            }
        sort(v+1,v+1+tot,cmp);
        for(int i=1;i<=n;i++)    fa[i]=i;
        for(int i=1;i<=tot;i++){
            int dx=find(v[i].x);
            int dy=find(v[i].y);
            if(dx==dy)    continue;
            fa[dy]=dx;sum++;
            ans+=v[i].z;
            if(sum==n-1)    break;
        }
        cout<<ans<<endl;
    }
    
}