delete pics to save space

2.1615.cpp

@@ -0,0 +1,38 @@
+#include<cstdio>
+#include<map>
+#include<cmath>
+using namespace std;
+double L,D;
+int n,res;
+map<double,double> mp;
+int main()
+{
+#ifdef local
+	freopen("pro.in","r",stdin);
+#endif
+	while(scanf("%lf",&L)==1)
+	{
+		scanf("%lf%d",&D,&n);
+		mp.clear();
+		double x,y;
+		for(int i=0;i<n;i++)
+		{
+			scanf("%lf%lf",&x,&y);
+			double &t=mp[x];
+			if(abs(y)>t) t=abs(y);
+		}
+		double now=-1000000;
+		res=0;
+		for(auto it=mp.begin();it!=mp.end();it++)
+			//        y*y+x*x
+			if(sqrt(it->second*it->second
+			+abs(now-it->first)*abs(now-it->first))>D)
+			{
+				//        x+sqrt(D*D-x*x)
+				now=it->first+sqrt(D*D-(it->second*it->second));
+				res++;
+			}
+		printf("%d\n",res);
+	}
+	return 0;
+}