1 #include<cstdio> 2 #include<cstring> 3 #include<algorithm> 4 #include<cstdlib> 5 #include<cmath> 6 #include<iostream> 7 #define inf 0x3f3f3f3f 8 using namespace std; 9 typedef long long ll;10 struct point{11     double x,y;12 }p[100002],tmp[100002];13 double dis(point &a,point &b){14     return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));15 }16 bool cmp1(point &a,point &b){17     return a.x<b.x;18 }19 bool cmp2(point &a,point &b){20     return a.y<b.y;21 }22 double closet(int l,int r){23     if(l==r) return inf;24     if(l+1==r) return dis(p[l],p[r]);25     int mid=(l+r)>>1;26     double d1,d2,d;27     d1=closet(l, mid),d2=closet(mid+1, r);28     d=min(d1,d2);29     int k=0;30     for(int i=l;i<=r;i++){31         if(fabs(p[i].x-p[mid].x)<mid) tmp[k++]=p[i];32     }33     sort(tmp, tmp+k,cmp2);34     for(int i=0;i<k-1;i++){35         for(int j=i+1;j<k;j++){36             if(fabs(tmp[j].y-tmp[i].y)>=d) break;37             d=min(d,dis(tmp[i],tmp[j]));38         }39     }40     return d;41 }42 43 44 int main(){45     int n;46     while(scanf("%d",&n)!=EOF){47         if(!n) continue;48         for(int i=0;i<n;i++){49             scanf("%lf%lf",&p[i].x,&p[i].y);50         }51         sort(p,p+n,cmp1);52         double ans=closet(0, n-1);53         printf("%.2f\n",ans/2);54     }55     56 }