Uva 10369 - Arctic Network

符合要求的最小生成树的最长边

2Y

第一次模板有回车=.=

#include<stdio.h>#include<vector>#include<algorithm>#include<math.h>#define MAX 1010struct edge{int p,q;double w;bool operator < (const edge& b)const {return w<b.w;}};std::vector<edge>L;int ft[MAX],rank[MAX],d[MAX];void in_ft(int n){int i;for(i=1;i<=n;i++)ft[i]=i,rank[i]=1,d[i]=0;}int find(int x){int t=x,temp;while(ft[x]!=x)x=ft[x];while(t!=x){temp=ft[t];ft[t]=x;t=temp;}return x;}void merge(int root1,int root2){int fr1=find(root1);int fr2=find(root2);ft[fr1]=fr2;rank[fr2]+=rank[fr1];rank[fr1]=0;find(root1);find(root2);}double x[MAX],y[MAX];double dis(int p,int q){double xx=x[p]-x[q];double yy=y[p]-y[q];return sqrt(xx*xx+yy*yy);}int main(){int t;scanf("%d",&t);while(t--){int n,m;scanf("%d%d",&n,&m);L.clear();in_ft(m);int i,j;for(i=1;i<=m;i++){scanf("%lf%lf",&x[i],&y[i]);for(j=1;j<i;j++){L.push_back( (edge){i,j,dis(i,j)} );}}std::sort(L.begin(),L.end());double res;int tmd=m;for(i=0;i<L.size();i++){if( find(L[i].p) != find(L[i].q) ){merge(L[i].p,L[i].q);d[ find(L[i].p) ]+=L[i].w;tmd--;if(tmd==n){res=L[i].w;break;}}}printf("%.2lf\n",res);//if(t)printf("\n");}return 0;}