2020-2021:teams:legal_string:王智彪:反演
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2020-2021:teams:legal_string:王智彪:反演 [2021/08/05 01:21] 王智彪 |
2020-2021:teams:legal_string:王智彪:反演 [2021/08/06 18:33] (当前版本) 王智彪 |
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| 两个图形相切，他们的反演图形也相切。 | 两个图形相切，他们的反演图形也相切。 | ||
| + | |||
| + | ===== 算法实现 ===== | ||
| + | |||
| + | <hidden 实现> | ||
| + | |||
| + | <code cpp> | ||
| + | |||
| + | struct Inversion { | ||
| + | Point o;//反演中心 | ||
| + | double r;//反演半径 | ||
| + | Inversion() {} | ||
| + | Inversion(Point _o,double _r) { | ||
| + | o=_o; | ||
| + | r=_r; | ||
| + | } | ||
| + | //点的反演 flag为0获取失败 1获取成功 | ||
| + | void getPointInv(Point a,Point &aa,int &flag) { | ||
| + | if(a==o) { | ||
| + | flag=0; | ||
| + | aa=a; | ||
| + | return; | ||
| + | } | ||
| + | Point ptmp=a-o; | ||
| + | double len=ptmp.len(); | ||
| + | ptmp=ptmp.trunc(r*r/len); | ||
| + | aa=o+ptmp; | ||
| + | flag=1; | ||
| + | } | ||
| + | //圆的反演 flag为1变成圆 -1变成直线 | ||
| + | void getCircleInv(circle c,Line &l,circle &cc,int &flag) { | ||
| + | if(c.relation(o)^1) { | ||
| + | Point p1,p2,pp1,pp2; | ||
| + | Line lt; | ||
| + | flag=1; | ||
| + | if(c.p==o) { | ||
| + | cc.p=o; | ||
| + | cc.r=r*r/c.r; | ||
| + | return; | ||
| + | } | ||
| + | lt=Line(c.p,o); | ||
| + | int ii=c.pointcrossline(lt,p1,p2); | ||
| + | int f; | ||
| + | getPointInv(p1,pp1,f); | ||
| + | getPointInv(p2,pp2,f); | ||
| + | Point pp=(pp1+pp2)/2; | ||
| + | cc.p=pp; | ||
| + | cc.r=pp1.distance(pp2)/2; | ||
| + | return; | ||
| + | } | ||
| + | flag=-1; | ||
| + | Point ptmp=c.p*2-o,pptmp,p1,p2; | ||
| + | int f; | ||
| + | getPointInv(ptmp,pptmp,f); | ||
| + | p1=o-pptmp; | ||
| + | p1=p1.rotleft(); | ||
| + | p1=p1+pptmp; | ||
| + | l=Line(pptmp,p1); | ||
| + | } | ||
| + | //直线的反演 成圆 | ||
| + | void getLineInv(Line L,circle &cc,int &flag) { | ||
| + | if(L.relation(o)==3) { | ||
| + | flag=0; | ||
| + | return; | ||
| + | } | ||
| + | flag=1; | ||
| + | Point p=L.lineprog(o),ans; | ||
| + | int f; | ||
| + | getPointInv(p,ans,f); | ||
| + | cc.r=ans.distance(o)/2; | ||
| + | cc.p=(ans+o)/2; | ||
| + | } | ||
| + | } iv; | ||
| + | |||
| + | |||
| + | </code> | ||
| + | |||
| + | </hidden> | ||
| ===== 代码练习 ===== | ===== 代码练习 ===== | ||
2020-2021/teams/legal_string/王智彪/反演.1628097664.txt.gz · 最后更改: 2021/08/05 01:21 由 王智彪
