delete pics to save space

1.3737.cpp

@@ -0,0 +1,38 @@
+#include<cstdio>
+#include<cmath>
+#include<algorithm>
+using namespace std;
+const int maxn=105;
+struct Node { double L,R; };
+inline bool operator<(const Node &a,const Node &b) { return a.L<b.L; }
+int n,R,res;
+Node a[maxn];
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	scanf("%d%d",&n,&R);
+	for(int i=0;i<n;i++)
+	{
+		int x,y; scanf("%d%d",&x,&y);
+		double t=sqrt(R*R-y*y);
+		a[i].L=x-t; a[i].R=x+t;
+	}
+	sort(a,a+n);
+	int q[maxn],cnt=0;
+	for(int i=0;i<n;i++)
+	{
+		while(cnt>0&&a[q[cnt-1]].R>=a[i].R) cnt--;
+		q[cnt++]=i;
+	}
+	double last=-10000000;
+	for(int i=0;i<cnt;i++)
+		if(a[q[i]].L>last)
+		{
+			res++;
+			last=a[q[i]].R;
+		}
+	printf("%d\n",res);
+	return 0;
+}