#include <iostream>#include <stdio.h>#include <iomanip>#include <algorithm>#include <cmath>using namespace std;const int N=200000+1;const double INF=1e100;struct Point{ double x,y; bool flag;};Point m[N+1];int tmp[N+1];double dis(Point p1,Point p2){ return sqrt((p1.x-p2.x)*(p1.x-p2.x)+(p1.y-p2.y)*(p1.y-p2.y));}double minL(double l1,double l2){ return l1<=l2?l1:l2;}bool cmpy(int a,int b){ return m[a].y<m[b].y;}bool cmpx(Point a,Point b){ return a.x<b.x;}double getMinLen(Point *s,int left,int right){ double rs=INF; if(left == right) return rs; if(left+1 == right) { if(s[left].flag == s[right].flag) return rs; return dis(s[left],s[right]); } int mid=(left+right)>>1; rs=getMinLen(s,left,mid); rs=minL(rs,getMinLen(s,mid+1,right)); int i,j,num=0; for(i=left;i<=right;++i) { if(fabs(s[i].x-s[mid].x)<=rs) tmp[num++]=i; } sort(tmp,tmp+num,cmpy); double d=INF; for(i=0;i<num;++i) { for(j=i+1;j<num;++j) { if(fabs(s[tmp[i]].y-s[tmp[j]].y)>=rs) break; if(s[tmp[i]].flag!=s[tmp[j]].flag && (d=dis(s[tmp[i]],s[tmp[j]]))<rs) rs=d; } } return rs;}int main(){ int t,n,i; scanf("%d",&t); while(t--) { scanf("%d",&n); for(i=0;i<n;++i) { scanf("%lf%lf",&m[i].x,&m[i].y); m[i].flag=0; } for(i=0;i<n;++i) { scanf("%lf%lf",&m[i+n].x,&m[i+n].y); m[i+n].flag=1; } n<<=1; sort(m,m+n,cmpx); double ans=getMinLen(m,0,n-1); cout<<setiosflags(ios::fixed)<<setprecision(3)<<ans<<endl; } return 0;}
