Calculate geometry, beginning of code

#include <iostream>#include<cmath>#include<vector>#include<string.h>#include<stdlib.h>#include<algorithm>using namespacestd;#defineMax_n 110/////////////////////////////////////////////////////////////////////Constant AreaConst DoubleINF = 1e10;//infinitely LargeConst DoubleEPS = 1e-8;//Calculation AccuracyConst DoublePI = ACOs (-1.0);//PI////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////type definition AreastructPoint {//two-dimensional points or vectors    Doublex, y; Doubleangle, dis; Point () {}, point (DoubleX0,Doubley0): X (x0), Y (y0) {}};structPoint3D {//three-dimensional point or vector    Doublex, y, Z; Point3D () {} Point3D (DoubleX0,DoubleY0,Doublez0): X (x0), Y (y0), Z (z0) {}};structLine {//Two-dimensional lines or segmentsPoint P1, p2; Line () {} line (point P10, point P20): P1 (P10), p2 (P20) {}};structLine3d {//three-dimensional lines or segmentsPoint3D p1, p2; Line3d () {} line3d (Point3D P10, Point3D P20): P1 (P10), p2 (P20) {}};structRect {//the method W, H, which represents the rectangle with a long width, representing the width and height, respectively    DoubleW, H; Rect () {} rect (Double_w,Double_h): W (_w), H (_h) {}};structrect_2 {//represents the rectangle, the lower-left coordinate is (XL, yl), and the upper-right coordinate is (XH, YH)    DoubleXL, YL, XH, YH; Rect_2 () {} rect_2 (Double_XL,Double_yl,Double_XH,Double_yh): XL (_XL), YL (_yl), XH (_XH), YH (_YH) {}};structCircle {//roundPoint C; DoubleR; Circle () {} circle (point _c,Double_r): C (_c), R (_r) {}};typedef vector<Point> Polygon;//two-dimensional polygontypedef vector<point> Points;//Two-dimensional point settypedef vector<point3d> POINTS3D;//three-dimensional point set////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////Basic Function AreaInlineDoubleMaxDoubleXDoubley) {    returnx > y?x:y;} InlineDoubleMinDoubleXDoubley) {    returnx > y?y:x;} InlineBOOLZERO (DoubleX//x = = 0{    return(Fabs (x) <EPS);} InlineBOOLZERO (Point P)//p = = 0{    return(ZERO (p.x) &&ZERO (P.Y));} InlineBOOLZERO (Point3D p)//p = = 0{    return(zero (p.x) && Zero (P.Y) &&ZERO (P.Z));} InlineBOOLEQ (DoubleXDoubleY//Eqaul, x = = y{    return(Fabs (x-y) <EPS);} InlineBOOLNEQ (DoubleXDoubleY//Not equal, X! = y{    return(Fabs (x-y) >=EPS);} InlineBOOLLT (DoubleXDoubleY//Less than, x < y{    return(NEQ (x, y) && (x <y));} InlineBOOLGT (DoubleXDoubleY//greater than, x > y{    return(NEQ (x, y) && (x >y));} InlineBOOLLEQ (DoubleXDoubleY//Less equal, x <= y{    return(EQ (x, y) | | (X <y));} InlineBOOLGEQ (DoubleXDoubleY//greater equal, x >= y{    return(EQ (x, y) | | (X >y));}//Attention!!! //if it's a very small negative floating-point number,//when the output of a valid number of digits is preserved, it will appear-0.000 in this form,//There 's a minus sign in front.//this can lead to error!!!!!! //so before you output a floating-point number, be sure to call the secondary function to fix it! InlineDoubleFIX (Doublex) {    return(Fabs (x) < EPS)?0: x;}/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////two-dimensional vector operationBOOL operator==(Point P1, point p2) {return(EQ (p1.x, p2.x) &&EQ (P1.Y, P2.y));}BOOL operator!=(Point P1, point p2) {return(NEQ (p1.x, p2.x) | |NEQ (P1.Y, P2.y));}BOOL operator<(Point P1, point p2) {if(NEQ (p1.x, p2.x)) {return(P1.x <p2.x); } Else {        return(P1.y <p2.y); }}pointoperator+(Point P1, point p2) {returnPoint (p1.x + p2.x, P1.y +p2.y);} Pointoperator-(Point P1, point p2) {returnPoint (p1.x-p2.x, P1.y-p2.y);}Double operator* (Point P1, point p2)//Calculate fork Multiply P1xp2{    return(p1.x * p2.y-p2.x *p1.y);}Double operator& (Point P1, point p2) {//Calculate dot product p1 p2    return(p1.x * p2.x + p1.y *p2.y);}DoubleNorm (Point P)//calculating the modulus of the vector p{    returnsqrt (p.x * p.x + p.y *p.y);}//angle the vector p rotation angle (in radians)//angle > 0 means counterclockwise rotation//Angle < 0 means clockwise rotationPoint Rotate (Point P,Doubleangle)    {point result; Result.x= p.x * cos (angle)-p.y *sin (angle); Result.y= p.x * sin (angle) + p.y *cos (angle); returnresult;}//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////three-dimensional vector operationBOOL operator==(Point3D p1, Point3D p2) {return(eq (p1.x, p2.x) && eq (p1.y, p2.y) &&EQ (p1.z, p2.z));}BOOL operator<(Point3D p1, Point3D p2) {if(NEQ (p1.x, p2.x)) {return(P1.x <p2.x); } Else if(NEQ (P1.Y, p2.y)) {return(P1.y <p2.y); } Else {        return(P1.z <p2.z); }}point3doperator+(Point3D p1, Point3D p2) {returnPoint3D (p1.x + p2.x, P1.y + p2.y, P1.z +p2.z);} Point3Doperator-(Point3D p1, Point3D p2) {returnPoint3D (p1.x-p2.x, P1.Y-P2.Y, P1.z-p2.z);} Point3Doperator* (Point3D p1, Point3D p2)//Calculate fork Multiply P1 x p2{    returnPoint3D (P1.Y * p2.z-p1.z *p2.y, P1.z* p2.x-p1.x *p2.z, p1.x* P2.Y-P1.Y *p2.x);}Double operator& (Point3D p1, Point3D p2) {//Calculate dot product p1 p2    return(p1.x * p2.x + p1.y * p2.y + p1.z *p2.z);}DoubleNorm (Point3D p)//calculating the modulus of the vector p{    returnsqrt (p.x * p.x + p.y * p.y + p.z *p.z);}BOOLOnlineseg (point P, line L)//determine if the point P on the two-dimensional plane is on the line L{    return(ZERO (l.p1-p) * (l.p2-p)) &&LEQ ((p.x-l.p1.x) * (p.x-l.p2.x),0) &&LEQ ((p.y-L.P1.Y) * (P.Y-L.P2.Y),0) );}

Calculate geometry, beginning of code