CodeForces 507B Amr and Pins

http://codeforces.com/problemset/problem/507/B

水题

#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#include<cmath>
using namespace std;
int main()
{
	double r,x,y,xx,yy;
	while(cin>>r>>x>>y>>xx>>yy)
	{
		double res=sqrt((xx-x)*(xx-x)+(yy-y)*(yy-y));
			res/=r*2;
			int ans=(int)res;
			if(ans!=res)
				ans++;
			cout<<ans<<endl;
	}
	return 0;
}