poj3301Texas Trip(三分)

 1 #include <iostream>
 2 #include<cstdio>
 3 #include<cstring>
 4 #include<algorithm>
 5 #include<stdlib.h>
 6 #include<vector>
 7 #include<cmath>
 8 #include<queue>
 9 #include<set>
10 using namespace std;
11 #define N 510
12 #define LL long long
13 #define INF 0xfffffff
14 const double eps = 1e-8;
15 const double pi = acos(-1.0);
16 const double inf = ~0u>>2;
17 struct point
18 {
19     double x,y;
20     point(double x =0 ,double y = 0):x(x),y(y){}
21 }p[N];
22 int n;
23 point rotate(point a,double rad)
24 {
25     return point(a.x*cos(rad)-a.y*sin(rad),a.x*sin(rad)+a.y*cos(rad));
26 }
27 double calc(double k)
28 {
29     int i;
30     double minx = INF,miny = INF;
31     double maxx = -INF,maxy = -INF;
32     for(i = 1 ; i <= n; i++)
33     {
34         point pp;
35         pp = rotate(p[i],k);
36         minx = min(minx,pp.x),miny = min(miny,pp.y);
37         maxx = max(maxx,pp.x),maxy = max(maxy,pp.y);
38     }
39     return max(maxx-minx,maxy-miny);
40 }
41 double solve()
42 {
43     double M,RM;
44     double L = 0.0;
45     double R = pi/2;
46     while (L + eps < R)
47     {
48         M = (L + R) / 2;
49         RM = (M + R) / 2;
50         if (calc(M) < calc(RM))
51             R = RM;
52         else
53             L = M;
54     }
55     return calc(M);
56 }
57 int main()
58 {
59     int t,i;
60     cin>>t;
61     while(t--)
62     {
63         scanf("%d",&n);
64         for(i = 1 ;i  <= n ;i++)
65         {
66             scanf("%lf%lf",&p[i].x,&p[i].y);
67         }
68         double ans = solve();
69         printf("%.2f\n",ans*ans);
70     }
71     return 0;
72 }