poj1328

#include<IOSTREAM>#include <MATH.H>#include <algorithm>using namespace std;struct point{double left,right;}p[2010],temp;bool operator >(point a,point b){return a.left>b.left;}int main(){int r,n;int ca;while (cin>>n>>r&&(n||r)){double ix,iy;ca=0;bool flag;for(int i=0;i<n;i++){flag=false;cin>>ix>>iy;if(fabs(iy)>r)flag=true;else{p[i].left=ix-sqrt(r*r-iy*iy);p[i].right=ix+sqrt(r*r-iy*iy);}}cout<<"Case "<<ca+1<<": ";if(flag)cout<<-1<<endl;else{int count=1;sort(p,p+n);temp=p[0];for(int j=1;j<n;j++){if(p[i].left>temp.right){count++;temp=p[i];}else if(p[i].right<temp.right)temp.right=p[i].right;}cout<<count<<endl;}}return 0;}