ZOJ1360 POJ1328 Radar Installation, 贪心

原来做过的贪心

比较简单

View Code 
 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <math.h>
 4 #include <algorithm>
 5 using namespace std;
 6 struct node
 7 {
 8     int x,y;
 9 }il[10005];
10 struct re
11 {
12     double x1,x2;
13 }radar[10005];
14 int cmp(struct re a,struct re b)
15 {
16     return a.x2 < b.x2;
17 }
18 int main()
19 {
20     int i,n,cas = 0;
21     int d;
22     while(scanf("%d %d",&n,&d) && n||d)
23     {
24 
25         int leap;
26         leap = 1;
27         for(i = 0;i < n;i++)
28         {
29             scanf("%d %d",&il[i].x,&il[i].y);
30             radar[i].x1 = il[i].x-sqrt(1.0*d*d-il[i].y*il[i].y);
31             radar[i].x2 = il[i].x+sqrt(1.0*d*d-il[i].y*il[i].y);
32             if(il[i].y - d > 0 )
33             leap = 0;
34         }
35         if(!leap)
36         {
37              printf("Case %d: -1\n",++cas);
38             continue;
39         }
40         sort(radar,radar+n,cmp);
41         int ans;
42         double pre;
43         ans = 1;
44         pre = radar[0].x2;
45         for(i = 1;i < n;i++)
46         {
47             if(pre < radar[i].x1)
48             pre = radar[i].x2,ans++;
49         }
50         printf("Case %d: %d\n",++cas,ans);
51 
52 
53 
54     }
55 }
posted @ 2012-11-06 20:15  某某。  阅读(195)  评论(0)  编辑  收藏  举报