#include <iostream>
#include <cstring>
#include <stdio.h>
#include <algorithm>
#include <cmath>
#include <map>
#include <vector>
using namespace std;

int n;
double d; 
struct Node{
	double l,r;
}node[1010];
bool cmp(const Node& x, const Node& y) {
	if(fabs(x.r - y.r) < 1e-5) {
		return x.l < y.l;
	}
	return x.r < y.r; 
}
int main() {
	int C = 1;
	while(scanf("%d%lf",&n,&d),n + d) {
		double rmax = -0x3f3f3f3f;
		bool ok = true;
		for(int i = 0;i < n;i ++) {
			double x,y;
			scanf("%lf%lf",&x,&y);
			if(d < y) {
				ok = false;
				continue;
			}
			double dx = sqrt(d * d - y * y);
			node[i].r = x + dx; 
			node[i].l = x - dx;
			rmax = max(rmax,node[i].r);
		}

		if(ok == false) {
			printf("Case %d: %d\n",C++,-1);
			continue;
		}
		sort(node,node+n,cmp);
		int ret = 0;
		int index = 0;
		double end;
		do {
			end = node[index].r;
			while(index < n && (node[index].l < end || fabs(node[index].l - end) < 1e-5)) {
				index ++;
			}
			ret ++;
			if(index >= n) {
				break;
			}
		}while(end < rmax || fabs(end-rmax) > 1e-5);
		printf("Case %d: %d\n",C++,ret);
	}
}

• Re:1A贴个代码 (1260) 20142430124 2016-05-20 20:24:01