求出**點的座標，就成了多邊形與圓相交面積的模板題了。。。
#include#include#include#include#include#include#include#include#include#include#include#include#include#include#define ff(i, a, b) for(int i=a; i=b; i--)
#define rep(i, n) for(int i=0; it sqr(t x)
vector operator + (vector a, vector b)
vector operator - (vector a, vector b)
vector operator * (vector a, double p)
vector operator / (vector a, double p)
bool operator < (const point& a, const point& b)
int dcmp(double x)
bool operator == (const point& a, const point& b)
double dot(vector a, vector b)
double length(vector a)
double angel(vector a, vector b)
double cross(vector a, vector b)
double torad(double d)
vector vecunit(vector x) //單位向量
vector normal(vector x) //垂直法向量
point getintersection(line a, line b) //線段交點
bool onsegment(point p, point a1, point a2)
bool incircle(point x, circle c)
bool oncircle(point x, circle c)
double angle(vector x)
//直線與圓交點
int getlinecircleintersection(line l, circle c, double& t1, double& t2, vector& sol)
t1 = (-f-sqrt(delta))/(2*e); sol.pb(l.point(t1));
t2 = (-f+sqrt(delta))/(2*e); sol.pb(l.point(t2));
return 2;
}//線段與圓的焦點
int getsegcircleintersection(line l, circle c, point* sol)
double segcirclearea(circle c, point a, point b) //線段切割圓
double polyciclrarea(circle c, point *p, int n)//多邊形與圓相交面積
if (cnt == 1)
if (cnt == 2)
}return fabs(ret);
}int n;
double x, y, v, ang, t, g, r;
circle c;
point p[maxn];
int main()
return 0;
}
HDU2036（多邊形面積）
解題思路 相鄰兩個座標的叉積和，最後除以2.0即求得多邊形面積。因為題目中逆時針序給出，所以輸入時逆著儲存。完整 include include include include include include include include include include include inclu...
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