思路：

求一遍凸包

用三角形面积（叉积求一下）/边长

求出来高，跟半径比一比

坑点：凸包上三点共线

//By SiriusRen#include 
     
      #include 
      
       #include 
       
        using namespace std;#define eps 1e-9const int N=1005;int n,top,k,f;double r;struct Point{
   double x,y;}point[N],tubao[N],cir;Point operator-(Point a,Point b){Point c;c.x=a.x-b.x,c.y=a.y-b.y;return c;}bool operator<(Point a,Point b){
   return abs(a.x-b.x)
        
         
          
           r-eps;}int main(){ while(scanf("%d",&n)){ if(n<3)break;top=f=0; scanf("%lf%lf%lf",&r,&cir.x,&cir.y); for(int i=1;i<=n;i++)scanf("%lf%lf",&point[i].x,&point[i].y); sort(point+1,point+1+n); for(int i=1;i<=n;i++){ while(top>1&&cross(tubao[top],point[i],tubao[top-1])<-eps)top--; tubao[++top]=point[i]; }k=top; for(int i=n-1;i;i--){ while(top>k&&cross(tubao[top],point[i],tubao[top-1])<-eps)top--; tubao[++top]=point[i]; } if(top!=n+1){puts("HOLE IS ILL-FORMED");continue;} for(int i=1;i<=n;i++)if(!check(tubao[i],tubao[i+1]))f=1; for(int i=1;i<=n;i++) if(chaji(tubao[i+1]-tubao[i],cir-tubao[i])<0)f=1; printf("PEG WILL %sFIT\n",f?"NOT ":""); }}