double getarea(int a, int b, int c)
{ int t1, t2, t3;
  double s1, s2, s3;
	t1 = (c + n - a) % n;
	s1 = d * sin(t1 * alph) / 2;
	t2 = (b + n - a) % n;
	s2 = d * sin(t2 * alph) / 2;
	t3 = (c + n - b) % n;
	s3 = d * sin(t3 * alph) / 2;
	return s2 + s3 - s1;
}


调用的时候修改为

getarea(0, cc[p], cc[i]);
getarea(0, cc[p - 1], cc[i]);
getarea(cc[i], cc[q], 0);
getarea(cc[i], cc[q - 1], 0);

• d = d * d / 4.0 .... (2) Bluebird 2005-07-21 21:25:04
• 我用的是向量差积算面积 (439) windbells 2005-07-21 22:27:07
  • 汗....那不就是行列式.... (0) Bluebird 2005-07-22 12:30:40