UVALive 4168

 1 #include<stdio.h>
 2 #include<string.h>
 3 #include<map>
 4 #include<vector>
 5 #include<iostream>
 6 #include<math.h>
 7 using namespace std;
 8 
 9 int main()
10 {
11     double dis, st, ed;
12     int cnt = 0;
13     while(~scanf("%lf%lf%lf", &dis, &st, &ed))
14     {
15         if (dis == 0) break;
16         int x, y;
17         bool flag = true;
18         int fx, fy;
19         while(scanf("%d%d", &x, &y))
20         {
21             if (x == -1 && y == -1)
22                 break;
23             if (flag == false) continue;
24             fx = x;
25             fy = y;
26             double tx, ty;
27             if (x != st)
28             {
29                 double k = (y-ed) * 1.0 / (x-st);
30                 if (k < 0) k = -k;
31                 double ang = atan(k);
32                 tx = dis*cos(ang);
33                 ty = dis*sin(ang);
34             }
35             else if (x == st)
36             {
37                 tx = 0;
38                 ty = dis;
39             }
40             double yy = (y-ed)*(y-ed);
41             double xx = (x-st)*(x-st);
42             double dd = sqrt((yy+xx));
43 
44             if (dd <= dis + 1)
45             {
46                 flag = false;
47                 continue;
48             }
49             if (x >= st) st += tx;
50             else st -= tx;
51             if (y >= ed) ed += ty;
52             else ed -= ty;
53             if (st < 0) st = 0;
54             if (ed < 0) ed = 0;
55         }
56         if (flag) printf("Firefly %d not caught\n", ++cnt);
57         else  printf("Firefly %d caught at (%d,%d)\n", ++cnt, fx, fy);
58     }
59     return 0;
60 }