BZOJ 1601 USACO 2008 Oct. 灌水

 1 #include<cstdio>
 2 #include<algorithm>
 3 using namespace std;
 4 const int maxn=400,maxm=200010;
 5 int n,fa[maxn],tot=0,num=0;
 6 long long ans=0;
 7 struct edge{int x,y,w;}e[maxm];
 8 void read(int &k){
 9     k=0; int f=1; char c=getchar();
10     while(c<‘0‘||c>‘9‘)c==‘-‘&&(f=-1),c=getchar();
11     while(‘0‘<=c&&c<=‘9‘)k=k*10+c-‘0‘,c=getchar();
12     k*=f;
13 }
14 int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
15 bool cmp(edge a,edge b){return a.w<b.w;}
16 int main(){
17     read(n); for (int i=0;i<=n;i++) fa[i]=i;
18     for (int i=1;i<=n;i++)e[++tot].x=i,e[tot].y=0,read(e[tot].w);
19     for (int i=1;i<=n;i++)
20     for (int j=1;j<=n;j++)e[++tot].x=i,e[tot].y=j,read(e[tot].w);
21     sort(e+1,e+1+tot,cmp);
22     for (int i,x,y=1;i<=tot;i++){
23         if (find(x=e[i].x)!=find(y=e[i].y)){
24             ans+=e[i].w; fa[find(x)]=find(y); num++;
25         }
26         if (num==n) break;
27     }
28     return printf("%lld\n",ans),0;
29 }