Quoit Design

 1 #include"iostream"
 2 #include"algorithm"
 3 #include"cmath"
 4 #include"cstdio"
 5 using namespace std;
 6 #define min(a,b) ((a)>(b))?(b):(a)
 7 struct point
 8 {
 9     double x,y;
10 }a[100003];
11 bool cmp(const point &a,const point &b)
12 {
13     if(a.x==b.x)
14       return a.y<b.y;
15     return a.x<b.x;  
16 }
17 double dis(point a,point b)
18 {
19     return sqrt(pow(a.x-b.x,2)+pow(a.y-b.y,2));
20 }
21 double S(point a[],int n)
22 {
23     double m=0xffffff;
24     if(n==2)
25       return dis(a[0],a[1]);
26     for(int i=0;i<n-2;i++)
27     {
28         m=min(m,min(dis(a[i],a[i+1]),min(dis(a[i],a[i+2]),dis(a[i+1],a[i+2]))));
29     }  
30     return m;
31 }
32 int main()
33 {
34     int n;
35     while(scanf("%d",&n),n)
36     {
37         for(int i=0;i<n;i++)
38         {
39             scanf("%lf%lf",&a[i].x,&a[i].y);
40         }
41         sort(a,a+n,cmp);
42         printf("%.2lf\n",S(a,n)/2);
43     }
44     return 0;
45 }