hdu3228Island Explorer

链接

给你两条线及两条线上的点，求最小生成树。

可以挨个枚举一条线上的点，三分出另一条线上离他最近的点进行连边。

注意N、M可能为0

debug了1天半，至今不知道原始二分版本错在哪里。。

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 #include<vector>
 #include<cmath>
 #include<queue>
 #include<set>
 using namespace std;
 #define N 50010
 #define LL long long
 #define INF 0xfffffff
 const double eps = 1e-;
 const double pi = acos(-1.0);
 const double inf = ~0u>>;
 struct point
 {
     double x,y;
     int id;
     point(double x=,double y = ):x(x),y(y) {}
 } p[N],q[N];
 struct node
 {
     int u,v;
     double w;
 } ed[N<<];
 int fa[N],g;
 double t1[N],t2[N];
 point a,b,c,d;
 typedef point pointt;
 point operator -(point a,point b)
 {
     return point(a.x-b.x,a.y-b.y);
 }
 int dcmp(double x)
 {
     if(fabs(x)<eps) return ;
     return x<?-:;
 }

 double dis(point a)
 {
     return sqrt(a.x*a.x+a.y*a.y);
 }
 bool cmmp(node ta,node tb)
 {
     return ta.w<tb.w;
 }
 int findx(int x)
 {
     if(x!=fa[x])
         fa[x] = findx(fa[x]);
     return fa[x];
 }
 void add(point ta,point tb)
 {
     ed[++g].u = ta.id;
     ed[g].v = tb.id;
     ed[g].w = dis(ta-tb);
 }
 int main()
 {
     // freopen("data.in","r",stdin);
     // freopen("data.out","w",stdout);
     int t,i,n,m;
     int kk = ;
     cin>>t;
     while(t--)
     {
         scanf("%d%d",&n,&m);
         scanf("%lf%lf%lf%lf%lf%lf%lf%lf",&a.x,&a.y,&b.x,&b.y,&c.x,&c.y,&d.x,&d.y);
         for(i = ; i <= n+m ; i++)
             fa[i] = i;
         for(i = ; i < n; i++)
         {
             scanf("%lf",&t1[i]);

             // cout<<p[i].x<<" "<<p[i].y<<endl;
         }
         for(i = ; i< m; i++)
         {
             scanf("%lf",&t2[i]);

         }
         sort(t1,t1+n);
         sort(t2,t2+m);
         int h=;
         for(i=;i<n;i++)
             if(i==n-||t1[i]!=t1[i+])
                 t1[h++]=t1[i];
         n=h;
         h=;
         for(i=;i<m;i++)
             if(i==m-||t2[i]!=t2[i+])
                 t2[h++]=t2[i];
         m=h;
         for(i = ; i < n;i++)
         {
              p[i] = point(a.x*t1[i]+b.x*(-t1[i]),a.y*t1[i]+b.y*(-t1[i]));
              p[i].id = i+;
         }
         for(i =  ; i < m ; i++)
         {
             q[i] = point(c.x*t2[i]+d.x*(-t2[i]),c.y*t2[i]+d.y*(-t2[i]));
             q[i].id = i+n+;
         }
         g = ;
         double sum1 = ,sum2 = ;
         for(i =  ; i < n- ; i++)
         {
             add(p[i],p[i+]);
             sum1+=dis(p[i]-p[i+]);
         }
         for(i =  ; i < m- ; i++)
         {
             add(q[i],q[i+]);
             sum2+=dis(q[i]-q[i+]);
         }
         if(n==||m==)
         {

             printf("Case #%d: %.3lf\n",++kk,sum1+sum2);
             continue;
         }
         for(i = ; i < n; i++)
         {
 //            point pp ;
 //            if(dcmp(c.x-d.x)==0)
 //            pp = point(c.x,p[i].y);
 //            else
 //            pp = dispoint(c,d,p[i]);
 //            if(dcmp(pp.x-min(c.x,d.x))<=0||dcmp(pp.x-max(c.x,d.x))>=0)
 //            {
 //                add(i,n+1);
 //                if(n+2<n+m)
 //                add(i,n+2);
 //                if(n+m-1>n+1)
 //                add(i,n+m-1);
 //                add(i,n+m);
 //                continue;
 //            }
 //            int k = find(n+1,n+m,c,dis(pp-c));
             // cout<<p[k].id<<" "<<pp.x<<" "<<pp.y<<endl;
 //            add(i,k);
 //            if(k!=n+1)
 //            add(i,k-1);
 //            if(k!=n+m)
 //            add(i,k+1);
             int l, r;
             l = ;
             r = m-;
             while (r - l > )
             {
                 int mid1 = (r + l) >> ;
                 int mid2 = (mid1 + r) >> ;
                 if (dis(p[i]-q[mid1]) > dis(p[i]-q[mid2]))
                     l = mid1;
                 else
                     r = mid2;
             }
 //            int k = find(1,n,a,dis(pp-a));
             add(p[i],q[l]);
             add(p[i],q[r]);
             if(l->=)
                 add(p[i],q[l-]);
             if(r+<=m-)
                 add(p[i],q[r+]);
         }
         sort(ed+,ed+g+,cmmp);
         int num = ;
         double sum = ;
         for(i = ; i <= g; i++)
         {
             int tx = findx(ed[i].u);
             int ty = findx(ed[i].v);
             if(tx!=ty)
             {
                 fa[tx] = ty;
                 num++;
                 sum+=ed[i].w;
             }
         }
         printf("Case #%d: %.3f\n",++kk,sum);
     }
     return ;
 }