UVA 1151 Buy or Build（生成树+二进制枚举）

来源：互联网发布：美国钻井平台数据 9月2 编辑：程序博客网时间：2024/05/07 00:28

题意思路：见紫书

#include<bits/stdc++.h>using namespace std;const int maxn = 1000+10;const int maxm = 10000+10;#define INF 1e9int n,m;struct Edge{int u,v,dist;Edge(){}Edge(int u,int v,int dist):u(u),v(v),dist(dist){}bool operator<(const Edge&rhs)const{return dist < rhs.dist;}};struct point{int x,y;};point p[maxn];int fa[maxn];Edge e[maxn*maxn];int findset(int x){return fa[x]==-1?x:fa[x]=findset(fa[x]);}int di(point a,point b){return (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y);}int kruskal(){int sum = 0;int ans = 0;//sort(e,e+m);for (int i = 0;i<m;i++){        if (findset(e[i].u)!=findset(e[i].v)){fa[findset(e[i].u)]=findset(e[i].v);ans+=e[i].dist;if (++sum>=n-1)return ans;}}return ans;}int T,cas=1;vector<int>g[10];int c[10];int main(){scanf("%d",&T);while (T--){if (cas>1)printf("\n");cas++;int q;scanf("%d%d",&n,&q);for (int i = 0;i<q;i++){            int temp,cnt;g[i].clear();scanf("%d",&cnt);scanf("%d",&c[i]);for (int j = 0;j<cnt;j++){scanf("%d",&temp);g[i].push_back(temp);}}for (int i = 1;i<=n;i++)scanf("%d%d",&p[i].x,&p[i].y);m=0;        for (int i = 1;i<=n;i++)for (int j = i+1;j<=n;j++){e[m++]=Edge(i,j,di(p[i],p[j]));}sort(e,e+m);memset(fa,-1,sizeof(fa));int ans = kruskal();for (int s =0;s<(1<<q);s++){int cost = 0;memset(fa,-1,sizeof(fa));for (int j= 0;j<q;j++){if ((s>>j)&1) continue;cost+=c[j];for (int k = 1;k<g[j].size();k++){                     if (findset(g[j][k])!=findset(g[j][0])) { fa[findset(g[j][k])]=findset(g[j][0]); }}}ans = min(cost+kruskal(),ans);}printf("%d\n",ans);}}

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