【贪心】雷达问题

#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <deque>
#include <map>
#define range(i,a,b) for(int i=a;i<=b;++i)
#define LL long long
#define rerange(i,a,b) for(int i=a;i>=b;--i)
#define fill(arr,tmp) memset(arr,tmp,sizeof(arr))
using namespace std;
pair<double,double>aa[115];
int n,d;
void init(){

}
void swap(int&a,int&b){
    int tmp=a;
    a=b;
    b=tmp;
}
bool cmp(pair<double,double>a,pair<double,double>b){
    return a.second<b.second;
}
void solve(){
    int cas=0;
    while(cin>>n>>d,n,d){
        bool flag=true;
        double x,y;
        range(i,0,n-1){
            cin>>x>>y;
            if(!flag)continue;
            if(y>d){
                flag=false;
                continue;
            }
            aa[i].first=(x-sqrt(d*d-y*y));
            aa[i].second=(x+sqrt(d*d-y*y));
        }
        cout<<"Case "<<++cas<<": ";
        if(!flag){
            cout<<-1<<endl;
            continue;
        }
        sort(aa,aa+n,cmp);
        double tmp=-123845;int ans=0;
        range(i,0,n-1)if(tmp<aa[i].first){
            ++ans;tmp=aa[i].second;
        }
        cout<<ans<<endl;
    }
}
int main() {
    init();
    solve();
    return 0;
}