View Code #include <iostream>#include <cstdio>#include <cmath>#include <algorithm>#define min(x,y) ((x)<(y)?(x):(y))using namespace std;struct point{double x,y;point(){}point(double _x,double _y){x=_x;y=_y;}void get(){scanf("%lf%lf",&x,&y);}};const double EPS=1e-8;const int MAX=10005;point p[MAX],q[MAX],p1[MAX],q1[MAX],temp;int n,m,N,M;int DB(double x){if(x>EPS) return 1;if(x<-EPS) return -1;return 0;}double Dis(point a,point b){return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));}//判断p在向量ab的哪一侧//右侧：返回正值//左侧：返回负值//在向量ab上返回0double cross(point a,point b,point p){return (b.x-a.x)*(p.y-a.y)-(b.y-a.y)*(p.x-a.x);}int cmp(point a,point b){double x=Dis(a,temp),y=Dis(b,temp);int flag=DB(cross(temp,a,b));if(flag) return flag==1;return DB(x-y)<=0;}void Graham(point p[],int n,point q[],int &m){point t;int i,k=0,a,b;for(i=1;i<n;i++){a=DB(p[i].y-p[k].y);b=DB(p[i].x-p[k].x);if(a==-1||!a&&b==-1) k=i;}if(k!=0) t=p[0],p[0]=p[k],p[k]=t;temp=p[0];sort(p+1,p+n,cmp);q[0]=p[0];q[1]=p[1];p[n]=p[0];m=2;for(i=2;i<=n;i++){while(m>1&&DB(cross(q[m-2],q[m-1],p[i]))<=0) m--;q[m++]=p[i];}m--;}double getAngle(point a1,point a2,point b1,point b2){point t;t.x=b2.x-b1.x+a1.x;t.y=b2.y-b1.y+a1.y;return cross(a1,a2,t);}double Dis1(point a,point p,point q){double t1=(q.x-p.x)*(a.x-p.x)+(q.y-p.y)*(a.y-p.y);double t2=(p.x-q.x)*(a.x-q.x)+(p.y-q.y)*(a.y-q.y);if(DB(t1)!=-1&&DB(t2)!=-1) return fabs(cross(a,p,q))/Dis(p,q);return min(Dis(a,p),Dis(a,q));}//凸包最近对踵点double calMinDis(point p[],int n,point q[],int m){int sp=0,sq=0,i,a,b,tp,tq;double ans,flag;for(i=0;i<n;i++){a=DB(p[i].y-p[sp].y);b=DB(p[i].x-p[sp].x);if(a==-1||!a&&b==-1) sp=i;}for(i=0;i<m;i++){a=DB(q[i].y-q[sq].y);b=DB(q[i].x-q[sq].x);if(a==1||!a&&b==1) sq=i;}ans=Dis(p[sp],q[sq]);tp=sp;tq=sq;do{flag=DB(getAngle(p[sp],p[(sp+1)%n],q[sq],q[(sq+1)%m]));if(flag==0){ans=min(ans,Dis1(p[sp],q[sq],q[(sq+1)%m]));ans=min(ans,Dis1(p[(sp+1)%n],q[sq],q[(sq+1)%m]));ans=min(ans,Dis1(q[sq],p[sp],p[(sp+1)%n]));ans=min(ans,Dis1(q[(sq+1)%m],p[sp],p[(sp+1)%n]));sp=(sp+1)%n;sq=(sq+1)%m;}else if(flag==-1){ans=min(ans,Dis1(q[sq],p[sp],p[(sp+1)%n]));sp=(sp+1)%n;}else{ans=min(ans,Dis1(p[sp],q[sq],q[(sq+1)%m]));sq=(sq+1)%m;}}while(tp!=sp||tq!=sq);return ans;}int main(){while(scanf("%d%d",&n,&m),n||m){int i;for(i=0;i<n;i++) p[i].get();for(i=0;i<m;i++) q[i].get();Graham(p,n,p1,N);Graham(q,m,q1,M);double ans=calMinDis(p1,N,q1,M);printf("%.5lf\n",ans);}return 0;}