DLx

Posted 2020-08-19 既然选择了远方，便只顾风雨兼程

 

 

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cstdio>
 4 #include <cmath>
 5 using namespace std;
 6 const double eps=1e-8;
 7 const int N=55,M=3005;
 8 struct Point{int x,y;}c[N],r[N];
 9 double sqr(double x){return 1.0*x*x;}
10 double dis(Point a,Point b){return sqrt(sqr(a.x-b.x)+sqr(a.y-b.y));}
11 int T,n,m,k,col[M],row[M];
12 int U[M],D[M],L[M],R[M];
13 int H[N],C[N],vis[N],cnt;
14 struct DLX{
15   void Init(int n,int m){
16     for(int i=0;i<=m;i++){
17       L[i]=i-1;R[i]=i+1;
18       C[i]=0;U[i]=D[i]=i;
19     }L[0]=m;R[m]=0;cnt=m;
20     for(int i=1;i<=n;i++)H[i]=0;
21   }
22   void Link(int r,int c){
23     C[c]+=1;++cnt;
24     U[D[c]]=cnt;U[cnt]=c;
25     D[cnt]=D[c];D[c]=cnt;
26     row[cnt]=r;col[cnt]=c;
27     
28     if(H[r]){
29       L[R[H[r]]]=cnt;L[cnt]=H[r];
30       R[cnt]=R[H[r]];R[H[r]]=cnt;
31     }
32     else H[r]=L[cnt]=R[cnt]=cnt;
33   }
34   void Delete(int x){
35     for(int i=D[x];i!=x;i=D[i])
36       L[R[i]]=L[i],R[L[i]]=R[i];
37   }
38   void Resume(int x){
39     for(int i=U[x];i!=x;i=U[i])
40       L[R[i]]=i,R[L[i]]=i;
41   }
42   int F(){
43     int ret=0;
44     for(int c=R[0];c;c=R[c])vis[c]=0;
45     for(int c=R[0];c;c=R[c]){
46       if(vis[c])continue;ret+=1;
47       for(int i=D[c];i!=c;i=D[i])
48     for(int j=R[i];j!=i;j=R[j])
49       vis[col[j]]=1;vis[c]=1;
50     }
51     return ret;
52   }
53   bool Dance(int dep){
54     if(!R[0])return dep<=k;
55     if(dep+F()>k)return false;
56     int p=0;
57     for(int i=R[0];i;i=R[i])
58       if(!p||C[i]<C[p])p=i;
59     for(int i=D[p];i!=p;i=D[i]){
60       Delete(i);
61       for(int j=R[i];j!=i;j=R[j])Delete(j);
62       if(Dance(dep+1))return true;
63       for(int j=L[i];j!=i;j=L[j])Resume(j);
64       Resume(i);
65     }
66     return false;
67   }
68 
69   bool Check(double d){
70     Init(m,n);
71     for(int i=1;i<=m;i++)
72       for(int j=1;j<=n;j++)
73     if(d>=dis(r[i],c[j]))
74       Link(i,j);
75     return Dance(0);
76   }
77 }dlx;
78 
79 int main(){
80   scanf("%d",&T);
81   while(T--){
82     scanf("%d%d%d",&n,&m,&k);
83     for(int i=1;i<=n;i++)
84       scanf("%d%d",&c[i].x,&c[i].y);
85     for(int i=1;i<=m;i++)
86       scanf("%d%d",&r[i].x,&r[i].y);
87     double l=0,r=1e3;
88     while(r-l>=eps){
89       double mid=(l+r)/2;
90       if(dlx.Check(mid))r=mid;
91       else l=mid;
92     }
93     printf("%.6f\n",l);
94   }
95   return 0;
96 }