POJ 2784 Buy or Build 最小生成树

枚举方案后做最小生成树。

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const int maxn=1100;
const int maxm=10000;
int n,q;
vector<int>g[10];
int c[10];
struct Point{
    int x,y;
    int getValueTo(Point p){
        return (p.x-x)*(p.x-x)+(p.y-y)*(p.y-y);
    }
}p[maxn];
struct EDGE{
    int u,v,d;
    bool operator<(const EDGE& rhs) const{
        return d<rhs.d;
    }
}e[maxn*maxn];
int edge;
int pa[maxn];
void makeset(int n){
    for (int i=0;i<=n;i++) pa[i]=i;
}
int findset(int x){
    if (x!=pa[x]) pa[x]=findset(pa[x]);
    return pa[x];
}
bool unionset(int x,int y){
    x=findset(x);
    y=findset(y);
    if (x!=y) {
        pa[x]=y;
        return true;
    }
    return false;
}
int kruskal(){
    int ans=0;
    for (int i=0;i<edge;i++){
        if (unionset(e[i].u,e[i].v)){
            ans+=e[i].d;
        }
    }
    return ans;
}
int main(){
	while (~scanf("%d%d",&n,&q)){
        for (int i=0;i<q;i++){
            int cnt;
            scanf("%d%d",&cnt,&c[i]);
            for (int j=0;j<cnt;j++){
                int tmp;
                scanf("%d",&tmp);
                g[i].push_back(tmp);
            }
        }
        for (int i=1;i<=n;i++) scanf("%d%d",&p[i].x,&p[i].y);
        edge=0;
        for (int i=1;i<=n;i++){
            for (int j=i+1;j<=n;j++){
                e[edge].u=i;
                e[edge].v=j;
                e[edge++].d=p[i].getValueTo(p[j]);
            }
        }
        sort(e,e+edge);
        makeset(n);
        int ans=kruskal();
        for (int s=1;s<(1<<q);s++){
            makeset(n);
            int cost=0;
            for (int i=0;i<q;i++){
                if (s&(1<<i)){
                    cost+=c[i];
                    for (int j=1;j<sz(g[i]);j++){
                        unionset(g[i][j-1],g[i][j]);
                    }
                }
            }
            ans=min(ans,cost+kruskal());
        }
        printf("%d
",ans);
	}
	return 0;
}

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