多边形凸包。。。。
Board Wrapping
Submit Status Description Problem B Board Wrapping Input: standard input Time Limit: 2 seconds
The small sawmill in Mission, British Columbia, has develZ??http://www.2cto.com/kf/ware/vc/" target="_blank" class="keylink">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" corners tightly. The space occupied by the mould would thus be the interior of the frame.
InputOn the first line of input there is one integer, N <= 50, giving the number of test cases (moulds) in the input. After this line, N test cases follow. Each test case starts with a line containing one integer n, 1< n <= 600, which is the number of boards in the mould. Then n lines follow, each with five floating point numbers x, y, w, h, j where 0 <= x, y, w, h <=10000 and ?90° < j <=90°. The x and y are the coordinates of the center of the board and w and h are the width and height of the board, respectively. j is the angle between the height axis of the board to the y-axis in degrees, positive clockwise. That is, if j = 0, the projection of the board on the x-axis would be w. Of course, the boards cannot intersect.
OutputFor every test case, output one line containing the fraction of the space occupied by the boards to the total space in percent. Your output should have one decimal digit and be followed by a space and a percent sign (%).
Sample Input Output for Sample Input
Swedish National Contest
The Sample Input and Sample Output corresponds to the givenpicture
Source Root :: Competitive Programming 3: The New Lower Bound of Programming Contests (Steven & Felix Halim) :: (Computational) Geometry :: Polygon :: StandardRoot :: AOAPC I: Beginning Algorithm Contests -- Training Guide (Rujia Liu) :: Chapter 4. Geometry :: Geometric Algorithms in 2D :: Examples Root :: Competitive Programming 2: This increases the lower bound of Programming Contests. Again (Steven & Felix Halim) :: (Computational) Geometry :: Polygon - Standard Submit Status |
![]() |
#include#include #include #include #include #include using namespace std; const double eps=1e-6; int dcmp(double x) { if(fabs(x) vp,ch; // 点集凸包 // 如果不希望在凸包的边上有输入点,把两个 <= 改成 < // 注意:输入点集会被修改 vector CovexHull(vector & p) { sort(p.begin(),p.end()); p.erase(unique(p.begin(),p.end()),p.end()); int n=p.size(); int m=0; vector ch(n+1); for(int i=0;i 1&&Cross(ch[m-1]-ch[m-2],p[i]-ch[m-2])<=0) m--; ch[m++]=p[i]; } int k=m; for(int i=n-2;i>=0;i--) { while(m>k&&Cross(ch[m-1]-ch[m-2],p[i]-ch[m-2])<=0) m--; ch[m++]=p[i]; } if(n>1) m--; ch.resize(m); return ch; } double PolygonArea(vector & p) { int n=p.size(); doubl

