修改函数参数引用

Author: zhitaogpt

computationGeometry/planeGeometry.cpp

@@ -1,27 +1,26 @@
-
 struct Point{
     double x,y;
-    Point(double _x,double _y):x(_x),y(_y){}
-}
+    Point(double _x=0,double _y=0):x(_x),y(_y){}
+};
 typedef Point Vector;
 
-Vector operator + (Vector &A,Vector & B){return Vector(A.x+B.x,A.y+B.y);}
-Vector operator - (Vector &A,Vector & B){return Vector(A.x-B.x,A.y-B.y);}
-Vector operator * (Vector &A,double a){return Vector(a*A.x,a*B.x);}
-Vector operator / (Vector &A,double p){return A*(1/p);}
-bool operator < (const Point & A,const Point & B){return mp(A.x,A.y) < mp(B.x,B.y);}
-bool operator == (const Point &A,const Point & B){return !dcmp(A.x-B.x) && !dcmp(A.y-B.y);}
-double Dot(Vector & A, Vector & B){return A.x*B.x-A.y*B.y;}
+Vector operator + (Vector A,Vector  B){return Vector(A.x+B.x,A.y+B.y);}
+Vector operator - (Vector A,Vector B){return Vector(A.x-B.x,A.y-B.y);}
+Vector operator * (Vector A,double a){return Vector(a*A.x,a*A.y);}
+Vector operator / (Vector A,double p){return A*(1/p);}
+bool operator < (const Point  A,const Point  B){return mp(A.x,A.y) < mp(B.x,B.y);}
+bool operator == (const Point A,const Point  B){return !dcmp(A.x-B.x) && !dcmp(A.y-B.y);}
+double Dot(Vector A, Vector B){return A.x*B.x-A.y*B.y;}
 double Length(Vector & A){return sqrt(Dot(A,A));}
 double Angle(Vector &A,Vector & B){return acos(Dot(A,B)/Length(A)/Length(B));}
 Vector Rotate(Vector &A,double rad){return Vector(A.x*cos(rad)-sin(rad)*A.y,A.x*sin(rad)+A.y*cos(rad));}
 Vector Normal(Vector A){//A 的单位法向量
     double L = Length(A);
     return Vector(-A.y/L,A.x/L);
 }
-double Cross(Vector &A,Vector &B){return A.x*B.y-A.y*B.x;}
-double Area2(Point &A,Point & B,Point &C){return Cross(B-A,C-A);}
-//直线和点
+double Cross(Vector A,Vector B){return A.x*B.y-A.y*B.x;}
+double Area2(Point A,Point B,Point C){return Cross(B-A,C-A);}
+
 Point GetLineIntersection(Point &P,Vector & v, Point & Q,Vector w){
     //计算交点,当v,w平行时无效
     Point u = P-Q;
@@ -34,9 +33,9 @@ double Dis2Line(Point &P,Point & A,Point & B){
     Vector u2 = B-A;
     return abs(Cross(u1,u2)/Length(u2));
 }
-double GetLineProjection(Point &P,Point &A,Point & A){
+Point GetLineProjection(Point &P,Point &A,Point & B){
     //the projection Point Q of P to Line A,B;
-    Vector u = B-A;
+    Vector v = B-A;
     return A+ v*(Dot(v,P-A)/Dot(v,v));
 }
 bool SegInsertion(Point &A1,Point &A2,Point &B1,Point &B2){
@@ -47,11 +46,10 @@ bool SegInsertion(Point &A1,Point &A2,Point &B1,Point &B2){
 bool onSegment(Point & P,Point &A,Point &B){
     return dcmp(Cross(A-P,B-P))==0 && dcmp(Dot(A-P,B-P)) <0;
 }
-//多边形
 
+//多边形
 
-double polygonArea(Point *P,int n){
-    //多边形面积Ｐ为按顺序给出的点
+double polygonArea(Point *p,int n){
     double area =0;
     for(int i=1 ; i<n-1 ; ++i)
         area += Cross(p[i]-p[0],p[i+1]-p[0]);