POJ3714+最近点对

特判标记即可

 #include<stdio.h>
 #include<string.h>
 #include<stdlib.h>
 #include<math.h>
 #include<algorithm>
 using namespace std;
 const double eps = 1e-;
 const double inf = 9999999999.0;
 const int maxn =  ;
 struct Point{
     double x,y;
     int flag;
 };
 Point pnt[ maxn<< ],temp[ maxn<< ];
 double dis( Point a,Point b ){
     return sqrt( (a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y) );
 }
 int cmpxy( Point a,Point b ){
     if( a.x!=b.x )
         return a.x<b.x;
     else
         return a.y<b.y;
 }
 int cmpx( Point a,Point b ){
     return a.x<b.x;
 }
 int cmpy( Point a,Point b ){
     return a.y<b.y;
 }
 double solve( int L,int R ){
     if( L==R )
         return inf;
     if( L+==R ){
         if( pnt[L].flag==pnt[R].flag )
             return inf;
         else
             return dis( pnt[L],pnt[R] );
     }
     int mid = (L+R)/;
     double res,Ldis,Rdis;
     Ldis = solve( L,mid );
     Rdis = solve( mid+,R );
     res = min( Ldis,Rdis );
     int cnt = ;
     for( int i=L;i<=R;i++ ){
         if( fabs(pnt[i].x-pnt[mid].x)<=res ){
             temp[cnt++] = pnt[i];
         }
     }
     sort( temp,temp+cnt,cmpy );
     for( int i=;i<cnt;i++ ){
         for( int j=i+;j<cnt;j++ ){
             if( fabs( pnt[i].y-pnt[j].y )>res ) break;
             if( pnt[i].flag==pnt[j].flag ) continue;
             res = min( res,dis(pnt[i],pnt[j]) );
         }
     }
     return res;
 }

 int main(){
     int ca;
     scanf("%d",&ca);
     while( ca-- ){
         int n;
         scanf("%d",&n);
         for( int i=;i<n;i++ ){
             scanf("%lf%lf",&pnt[i].x,&pnt[i].y);
             pnt[i].flag = ;
         }
         for( int i=n;i<*n;i++ ){
             scanf("%lf%lf",&pnt[i].x,&pnt[i].y);
             pnt[i].flag = ;
         }
         sort( pnt,pnt+*n,cmpxy );
         double Ans = solve( ,*n- );
         printf("%.3lf\n",Ans);
     }
     return ;
 }