判断直线是否相交

最新推荐文章于 2021-11-01 16:37:59 发布

原创最新推荐文章于 2021-11-01 16:37:59 发布 · 610 阅读

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double x1,Y1,x2,y2,x3,y3,x4,y4;
bool line()
{
    double x=x2-x1,y=y2-Y1;
    //cout<<x<<' '<<y<<endl;
   // cout<<(x3-x1)<<' '<<(y3-Y1)<<endl;
    if(fabs(x*(y3-Y1)-y*(x3-x1))<1e-5&&fabs(x*(y4-Y1)-y*(x4-x1))<1e-5)
    return 1;
    return 0;
}
bool none()
{
    if(fabs((x2-x1)*(y4-y3)-(y2-Y1)*(x4-x3))<1e-5)
    return 1;
    return 0;
}
    if(line())
    cout<<"LINE"<<endl;
    else if(none())
    cout<<"NONE"<<endl;
    else
    {
    double a1=Y1-y2,b1=x2-x1,c1=x1*y2-x2*Y1,a2=y3-y4,b2=x4-x3,c2=x3*y4-x4*y3;
    double x=(c1*b2-c2*b1)/(a2*b1-a1*b2),y=(a2*c1-a1*c2)/(a1*b2-a2*b1);
    printf("POINT %.2f %.2f\n",x,y);
    }