Codeforces Round #172 (Div. 2) C.Rectangle Puzzle(几何)

题目链接

注意h > w的时候交换，还有就是注意一下转化double，错了好几次。。。算法就是解方程。。精度倒是不卡。

 1 #include <cstdio>
 2 #include <cstring>
 3 #include <cmath>
 4 #include <string>
 5 using namespace std;
 6 #define PI 3.1415926535898
 7 #define eps 1e-13
 8 double fun(double x)
 9 {
10     return x*PI/180;
11 }
12 int main()
13 {
14     int h,w,a,t;
15     double k1,k2,x,y,ha,sp,ans;
16     scanf("%d%d%d",&w,&h,&a);
17     if(h > w)
18     {
19         t = h;
20         h = w;
21         w = t;
22     }
23     ha = fun(a);
24     if(ha > fun(90.0))
25     {
26         ha = PI - ha;
27     }
28     sp = 2*(atan(h*1.0/w));
29     if(ha < sp)
30     {
31         k1 = (1 + 1/cos(ha));
32         k2 = tan(ha);
33         x = (h*k1-w*k2);
34         y = (h*k2-w*k1);
35         ans = (double)h*w - k2*(x*x + y*y)/((k1*k1-k2*k2)*(k1*k1-k2*k2));
36     }
37     else
38     {
39         ans = (double)h*h/sin(ha);
40     }
41     printf("%lf\n",ans+eps);
42     return 0;
43 }

 

posted @ 2013-03-11 21:12  Naix_x  阅读(242)  评论(0)    收藏  举报