题目
1 #include <iostream>
2 #include <cstdio>
3 #include <cstring>
4 #include <cstdlib>
5 #include <cmath>
6 #include <algorithm>
7 using namespace std;
8 double G[110][110], sum;
9 const double pi = acos(-1);
10 const int INF = (1<<28);
11
12 struct node
13 {
14 double x, y; //x是经度， y是纬度。
15 }p[110];
16
17 double angle(double lng1, double lat1, double lng2, double lat2)
18 {
19 double dlng = fabs(lng1-lng2)*pi/180;
20 while(dlng >= pi+pi)
21 dlng -= (pi+pi);
22 if(dlng > pi)
23 dlng = pi+pi-dlng;
24 lat1 *= pi/180;
25 lat2 *= pi/180;
26 return acos(cos(lat1)*cos(lat2)*cos(dlng)+sin(lat1)*sin(lat2));
27 }
28
29 double sphere_dist(double r, double lng1, double lat1, double lng2, double lat2)
30 {
31 return r*angle(lng1, lat1, lng2, lat2);
32 }
33
34 void prime(int n)
35 {
36 int i, j, pos;
37 int Min, vis[110];
38 double d[110];
39 memset(vis, 0, sizeof(vis));
40 memset(d, 0, sizeof(d));
41
42 for(i = 1; i <= n; i++)
43 d[i] = G[1][i];
44 vis[1] = 1;
45 for(i = 2; i <= n; i++)
46 {
47 Min = INF;
48 for(j = 1; j <= n; j++)
49 {
50 if(!vis[j] && Min>d[j])
51 {
52 Min = d[j];
53 pos = j;
54 }
55 }
56 sum += Min;
57 vis[pos] = 1;
58 for(j = 1; j <= n; j++)
59 {
60 if(!vis[j])
61 {
62 if(d[j] > G[pos][j])
63 d[j] = G[pos][j];
64 }
65 }
66 }
67 }
68 int main()
69 {
70 int n, t, c, i, j;
71 double d, l, r;
72 cin>>t;
73 while(t--)
74 {
75 sum = 0;
76 cin>>d>>l>>c;
77 r = d/2*1.0;
78 n = c;
79 for(i = 1; i <= n; i++)
80 {
81 for(j = 1; j <= n; j++)
82 G[i][j] = INF;
83 G[i][i] = 0;
84 }
85 for(i = 1; i <= n; i++)
86 cin>>p[i].x>>p[i].y;
87
88 for(i = 1; i <= n; i++)
89 for(j = i+1; j <= n; j++)
90 {
91 G[i][j] = sphere_dist(r, p[i].y, p[i].x, p[j].y, p[j].x);
92 G[j][i] = G[i][j];
93 }
94 prime(n);
95 if(sum - l> 0)
96 cout<<"N"<<endl;
97 else
98 cout<<"Y"<<endl;
99 }
100 return 0;
101 }
