[APIO2018] Select Circle (kd-tree)

Test instructions: give you n a circle, each time you select the largest radius, it and the circle that intersects it all deleted, the output of each circle is deleted at which time.

kd Tree template problem. Use a rectangular frame to hold the circle, and you can prune it directly. In order to prevent the card can rotate the point of an angle, in order to insure can also turn several angles.

1#include <cmath>2#include <cstdio>3#include <algorithm>4 #defineRep (i,l,r) for (int i= (l); i<= (R); i++)5typedefDoubledb;6 using namespacestd;7 8 Const intn=300010;9 ConstDB inf=1e20,eps=1e-3, Alpha=acos (-1)/3;Ten intN,rt,ans[n]; One db x,y,r; A structp{DB x,y,r;intID;} Cur,a[n]; - structtr{intls,rs; DB x1,y1,x2,y2; P C; }t[n]; -  the BOOLCMPX (ConstP &a,ConstP &b) {returna.x<b.x;} - BOOLCmpy (ConstP &a,ConstP &b) {returna.y<b.y;} - BOOLCMPR (ConstP &a,ConstP &b) {return(A.R==B.R)? A.id<b.id:a.r>B.R;} -  + voidFintXinty) { -T[x].x1=min (T[X].X1,T[Y].X1); T[x].x2=Max (t[x].x2,t[y].x2); +T[x].y1=min (T[X].Y1,T[Y].Y1); T[x].y2=Max (t[x].y2,t[y].y2); A } at  - voidUpdintx) { -     if(Ans[t[x].c.id]) t[x].x1=t[x].y1=inf,t[x].x2=t[x].y2=-inf; -     Else{ -T[X].X1=T[X].C.X-T[X].C.R; t[x].x2=t[x].c.x+T[X].C.R; -T[X].Y1=T[X].C.Y-T[X].C.R; t[x].y2=t[x].c.y+T[X].C.R; in     } -     if(T[X].LS) F (x,t[x].ls); to     if(t[x].rs) F (x,t[x].rs); + } -  the intBuildintLintRintk) { *     if(L>r)return 0; $     intMid= (l+r) >>1; Nth_element (a+l,a+mid,a+r+1K?cmpy:cmpx);Panax NotoginsengT[mid].c=A[mid]; -T[mid].ls=build (l,mid-1, k^1); T[mid].rs=build (mid+1, r,k^1); theUPD (mid);returnmid; + } A  theDB SQR (db x) {returnx*x;} + BOOLOut (intx) {return(t[x].x2<cur.x-cur.r-eps) | | (t[x].x1>cur.x+cur.r+eps) | | (t[x].y2<cur.y-cur.r-eps) | | (t[x].y1>cur.y+cur.r+EPS); } - BOOLCHK (P &a) {returnSqr (a.x-cur.x) +sqr (A.Y-CUR.Y) &LT;=SQR (A.R+CUR.R) +EPS;} $  $ voidQueintx) { -     if(Out (x))return; -     if(!ans[t[x].c.id] && chk (t[x].c)) ans[t[x].c.id]=cur.id; the     if(t[x].ls) que (t[x].ls); -     if(t[x].rs) que (t[x].rs);Wuyi } the  - intMain () { WuFreopen ("apiob.in","R", stdin); -Freopen ("Apiob.out","W", stdout); Aboutscanf"%d",&n); $Rep (I,1, N) -scanf"%LF%LF%LF", &x,&y,&r), a[i]= (P) {X*cos (alpha) +y*sin (Alpha), Y*cos (Alpha)-x*sin (alpha), r,i}; -Rt=build (1N0); Sort (A +1, a+n+1, CMPR); -Rep (I,1, N)if(!ans[a[i].id]) ans[a[i].id]=a[i].id,cur=A[i],que (RT); ARep (I,1, N) printf ("%d", Ans[i]); Puts""); +     return 0; the}

[APIO2018] Select Circle (kd-tree)