1 #include<iostream> 2 #include<cmath> 3 #include<stdlib.h> 4 #include<string.h> 5  6  7 using namespace std; 8  9 typedef struct10 {11     double start;12     double end;13 }SE;14 15 SE a[10002];16 17 int compare (const void *p1, const void *p2)18 {19     return (((SE *)p1)->start<((SE *)p2)->start)? 1:-1;20 }21 22 int main()23 {24     int T;25     cin>>T;26     while(T--)27     {28         int N;29         double w, h;30         cin>>N>>w>>h;31         for(int i=0; i<N; i++)32         {33             double x, r;34             cin>>x>>r;35             double tem = r*r-((double)h/2)*((double)h/2);36             if(tem>=0)37                 tem = sqrt(tem);38             else39                 tem = 0;40             a[i].start = x - tem;41             a[i].end = x+ tem;42         }43         qsort(a,N,(sizeof(a[0])),compare);44         /*for(int i=0; i<K; i++)45         {46             cout<<a[i].start<<"    "<<a[i].end<<endl;47         }*/48         double st=0, en=0;49         int visit[1002];50         memset(visit,0,sizeof(visit));51         int num = 0;52         while(en<w)53         {54             double endest = en;55             for(int i=0; i<N; i++)56             {57                 if(visit[i]==0&&a[i].start<=en&&a[i].end>endest)58                 {59                     endest = a[i].end;60                 }61             }62             if(endest>en)63             {64                 en = endest;65                 num++;66             }67             else68             {69                 cout<<0<<endl;70                 break;71             }72         }73         if(en>=w)74         {75             cout<<num<<endl;76         }77     }78     return 0;79 }