HAL Id: inria-00072904
https://hal.inria.fr/inria-00072904
Submitted on 24 May 2006
HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers.
L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
The union of Unit Balls has Quadratic Complexity, even if They all Contain the Origin
Hervé Brönnimann, Olivier Devillers
To cite this version:
Hervé Brönnimann, Olivier Devillers. The union of Unit Balls has Quadratic Complexity, even if They
all Contain the Origin. RR-3758, INRIA. 1999. �inria-00072904�
ISSN 0249-6399
a p p o r t
d e r e c h e r c h e
THÈME 2
INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET EN AUTOMATIQUE
The union of unit balls has quadratic complexity, even if they all contain the origin
Hervé Brönnimann — Olivier Devillers
N° 3758
Septembre 1999
Unité de recherche INRIA Sophia Antipolis
2004, route des Lucioles, B.P. 93, 06902 Sophia Antipolis Cedex (France)
Téléphone : 04 92 38 77 77 - International : +33 4 92 38 77 77 — Fax : 04 92 38 77 65 - International : +33 4 92 38 77 65
"#$ %'& )(*,+-. /0!,( 1"#2! / ! /3
4576/8:9<;6>=@??BADCFE)??HGJIKLAM8!AD5N6OP5Q8!ALKDKD5N6R
SUTWVXZY[\ ] ^_W`aYcbedgfQ`eh/`eY/b
Y/i.h>jkbeh/lWbnmpoNXq)dQba`er7lWY
sutpdkvwY/ixsytz`amzXZY
{xjk|W|@dgtpi.}WYctzY/h~TWYtph~TWY_ Qk\ Y/|iY/XqWtpYgQ\ Z|WjgfQYm
PB/>Wg Y.|WtzdN`e}Yxjcbad#Ytuq)dQlW_W}hdg_WmpiztzlWhi`adQ_mpTWd.`e_WfciTWjkiuiTWYUlW_`edQ_dg
lW_W` i q¡jgbabem¢`e_£x¤ T¡jgm¥r7l¡jk}Wtjkiz`ehhdQXZ|WbaY¦` i§oQ¨nY/gY_©`auizTWY/oªjgbabBhdg_7ijg`a_iTWY-dgtz`afQ`e_¬«
SUTW`em.mpY/izizbeY/m¥j2hdg_kvwYhilWtpYdkuT¡jktz`at«
¯® °¬±p²-³ ´g µ dQXZ|Wli~jkiz`edQ_Wjgb@fgYdQXZY/iztpog¨¡¶x_W`adQ_Pdknq¡jgbabem/¨¡] YdQXZY/iztz`ah¢Y¦WjkX|beY
+P / "'$ %/'&P !
dQlWm |WtpdQ|)dQmzdQ_m¥lW_WY2h/dQ_WmpiztzlWhi`adQ_©}lW_©Y_WmpYXqbeYZ}WY2q)dQlWbaYm }WY£ ¤
}WdQ_ i¥bl_W`edg_<jlW_ª_WdQXqtzYr7l¡jk}Wtjkiz`er7lWY}WYDjgh/YmxY/i¥}jgt/izYm« µ Ym¢q@dQlbeY/m¢dQ_ i¥bej
|¡jgtpiz`eh/lWbejgtz` i^ }jgdQ`at'baYxXXZYxtj>oQdQ_Y/i#}jgdQ`at'lW_WY `a_7izYtpmzYhi`adQ__WdQ_N`e}WYk« µ Y/ipiY
_WdgiYc}W^/XZdQ_ itzYclW_Yh/dQ_kvwY/h/iltzY^_WdQ_h^|¡jgt «)TWjgtz`at«
H³ ± F ] ^dQXZ^/iztz`aYjgbefgdQtz` iTWXZ`ar7lWYg¨'¶x_W`adQ_ }WYq@dglWbeY/m¨¦Y/X|beYfQ^dgX^
itz`ar7lWY
% & Zn!"J! /
SUTWYlW_`edQ_1dk.j¯mpY/i2dg('0q¡jgbabam`a_ £ ¤
T¡jgmr7l¡jk}Wtjkiz`ehhdQXZ|WbaY¦` i§o*),+#'.-/¨YQY/_1`a
iTWYojgbab¬T¡j>gYcizTWY¥mzjgXZYtzjg}W`alWm«10xbeb@iTWY jkbetpY>jg}o327_Wd._¯h/dQ_WmpiztzlWhi`adQ_Wm.T¡j>QY qWjgbebam
mzh>jiziY/tzY/}jgtzdglW_W}:¨NTWd'YQY/t¨jg_W}PT¡jgtp`etJ|)dQmzY/}iTWYx|WtzdgqWbeY/X .TWY/izTWYt'jr7l¡jg}Wtzjki`ah
hdQXZ|WbaY¦` i§o1hdQlbe} q)Yjgh~TW`aY/gY}0` xjgbab#iTYPq¡jgbabem54 dg mjgXZYtzjg}W`alWm6h/dQ_ i~jg`a_WY/} izTWY
dQtz`afQ`a_:«
7§_ciT`em!_WdgizYg¨'YJmzTWd jUh/dQ_WmpiztzlWhi`adQ_dk8'ZlW_W` i!q¡jgbabem/¨gjgbab hdg_7ijg`a_W`e_fxiTYJdgtz`afQ`e_¬¨
.TWdQmzYlW_W`adQ_T¡jgmxhdQXZ|WbaY¦` i§o9),+#'
-
/«:0¢m¢jitp`aN`ejgb!dQqWmzY/tpkjkiz`edQ_¬¨@#Y-dQqWmpYtpgYiTWjki
iTWYhY/_7izYtpm2jgtzYjgtpqW`aiztjgtp`eb o hbadQmzYidiTWYdQtz`afQ`a_ `a_ dQlth/dQ_WmpiztzlWhi`adQ_:«57§_ Djghi>¨`a
iTWY¥h/Y_ iY/tzm.jgtpY¢dQtphY}Pizd-q)Y jkiUbaY>jgmwiU|¡jg`atp.`amzY<;jg|Wjgtpi¨ dQt#mzdQXZY hdg_Wmpijg_ i(;>=@?¨
iTWY/_¯_WdZXZdQtpYcizT¡jg_BAC+D
EGF
/'hjg_XY/Y/i `a_ªj2mz`a_WfQbaY|@dQ`a_ i>¨¡jk_W}¯TY_Wh/YizTWYclW_W`adQ_T¡jgm
hdQXZ|WbaY¦` i§ojki#XZdQmpiHA3+ D
EF 'I/KJLA
E
+M'I/«N7 i,`amUjg_`a_ iY/tzYmwi`a_WfZdQ|)Y_Pr7lWY/mpi`adQ_P.T¡jiUj
hdQ_W}`aiz`edQ_©mpTWdQlWba}©q@Y-mpdiT¡jki¢iTWY-l_W`edg_ TWjgYZmzlWq)r7l¡jg}Wtzjki`ah2hdQXZ|WbaY¦` i§o©jg_W}<ogY/i
iTWYcq¡jgbabam TWjgYjktzqW` itzjgtz`abaohbadQmzYhY/_ iYtpm«
OJo h/dQ_ itjkmpi>¨izTWYP QR!ST$RU <dkV'q¡jgbabam-h>jg_ T¡j>QYr7l¡jg}Wtzjki`ahPh/dQXZ|WbeY¦`ai§o `a
iTWY/`et.tjk}W`e`:jgtzYc_Wdgi h/dQ_Wmpiztjg`a_WY/}:¨¡qWli.iTYh/dQXZ|WbaY¦`ai§o`am.be`a_WY>jkt ` yjkbeb¬izTWYctjg}`e`njgtpY
iTWYmjgXZYXW[YL« `aXZ`ebejgtzb oQ¨,izTWYhdQ_ QY¦T7lWbab dgZ' q¡jgbabemh>jg_ T¡j>QYjkbempd r7l¡jg}Wtzjki`ah
hdQXZ|WbaY¦` i§oXW [YL¨¡qWli.izT¡jki.hdgX|beY¦` i§o`em.ba`e_Y>jgt.` izTWY/ojgbab:T¡j>gYizTWYcmjgXZYctjg}`elWm/«
\ ] :n"J! /
^nYi_ jg_W}a`©q@Yjg_ o©`a_7izYfQY/tzm/«
Y}WY[b¡_Yi§#dªDjgXZ`eba`aYmdk,lW_W` iq¡jgbabem[ciTWY,b¡tpmpi
hdQ_Wmp`emwim¯dgd` lW_W` iq¡jgbabem.TWdQmpY h/Y_ iY/tzmba`eY©dQ_ j mzXjgbabcgYtwi`ah>jgbmzY/fQXZY_ ifeizTWY
mzYh/dQ_W} h/dQ_Wmp`emwimdk(_ lW_`aiq¡jgbabemc.TWdQmpYh/Y_ iY/tzm-ba`eYdQ_ j¯mpXjkbebuh`atzh/beYlW_W}WY/tizTWY
mzYfgXY/_ i>«H4LYYgB`efglWtzY#«6 Y#mzTWd q)Ybad1iT¡jki!iTY`atBlW_W`adQ_-TWjgmr7l¡jk}Wtjkiz`ehAC+U`_5/
hdQXZ|WbaY¦` i§oQ«
hi ® ! Dkj
DPl l l j<m
l Y}WY_WdkiYq o j +onIpSq/cizTWYq¡jgbab'h/Y_ iY/tzY} jkirnFjg_W}1dg
tjg}W`alWmdqN«X^ Yi,'sJt`vuw_ jg_W}yx{z.}Y_WdgizYPiTWY|)dQ`a_ iZdg hdNdQtz}W`a_¡jkizYm5+#?p?p|+M}1~
/"'R/¨,jg_W} j zJ j +UxzGp
/¨' dQtv} J
pffp`)«L7 i`amhbaY>jktiTWjkiizTWYq@dQl_W}¡jgtwo
dgV
DQ
z
m[j zJhdQ_mz`ampimdgJi§'dTWY/X`amz|TWYtpYmq)YbadQ_Wfg`e_Wfizd j D
jg_} j<m ba`a_82gY/} q o©j
_¡jgtztpdh/oNba`e_}WYtJdg@TWY`afQT iJbeY/mzmuiT¡jg_ `8' < '
¤
«BSUTW`emuhoba`a_W}WYtJhdg_7ijg`a_Wm'jkbebizTWY
h`atzhbaYmr j zP j z
D dQtV}J
pffp`>~
«4LYYgB`afQlWtpY2Q«6
{8f
g`efQltzY2 cySUTWYlW_W`adQ_P
DQ
z mj z «
hi ®
! D,j<m
D l l l j<m
l
^nYi q)Y¥iTWYc|)dQ`e_ i dghdNdQtz}`e_¡jiYm + p?p /'.` iT
J"!
'-K~$#
' p J ~%!
'.- ~&#
' ¤
4#0¢_ okjgbalWYmxmjkiz`emwMoN`e_WfiTWYhdQ_mpitzjg`a_7izm<x m('*)
`a_a4wT6 jg_},+ ) -
-
`e_ 4 [ 6,q)Ybad
'dQlbe}¯}WdW«6 Yc}WYRb¡_WY/.jgm.iTWYtzdki~jkiz`edQ_jgtpdQlW_W}iTWY0 §j¦`em dgyjk_WfQbaY
!21
_<¨)jg_W}
dQtUY>jgh~T43dJ pfff[pS_<¨5
m
76J8.
69
D +:/,jk_W}
jm
76VJ
j
+:
m
76Tp /«
; <
(Pn
O#odQlWt.h~TWdQ`ahYdg<jg_W}= ¨#Y|tzdQYq@Y/bed izT¡jki.iTWYq)dQlW_W}¡jktz`aYm dg j<m D
jg_W}dg
iTWY lW_W`adQ_ m
z?>
D j z@}WY/|W`ehiY/}`e_ g`efQltzY¢XZYYiUjgbadQ_WfjhltpQYA@.TW`eh~Tmjkiz`em b¡Ym'izTWY
i§'dhbejg`aXm q)Ybadc«uSUTWYcmp`aizl¡jki`adQ_`em.}WY/|W`ah/iY/}ªdQ_BgB`afQlWtpY[«
B DC E >$R !F@ QR!ST$RMIM j z.f!V}J ?pffp`DG
B DC H
I!U @@KJN $ T .RRMLk
j
DON
" R#QPRGSJN $
RRMLH: v
m
zQ>
- j zUT Z$ ." 55ML !VT$RQ!<:ML 3TR
!21
_
g¡tpdQXh/bjg`aX [¨'YhdQ_hbalW}WY iT¡ji izTWY |)dQtpiz`edQ_dg@.TW`ah~Tª}dY/mU_Wdgi q@Y/bedg_Wf2id
j D
`amh/dQ_ i~jg`a_WY/} `e_ iTWYq)dQlW_W}¡jktpo©dg,izTWYlW_W`adQ_ dg#iTWYv' J `du _ q¡jgbabem/¨ g¡tzdQX
hbejg`eX Q¨ 'YhdQ_hbalW}WYZiT¡jkicizTWYZ|@dQtwi`adQ_©dgV@ .TW`eh~T }WdNYmc_Wdgiq)YbadQ_Wfid j D T¡jgm
hdQXZ|WbaY¦` i§oXW+`8/«KgtpdQX hbejg`eX [¨izT¡jkiU` i.`emUh/dQ_ i~jg`a_WY/}`a_j2mzXjgbab jg_WfQlbjgt'mzYhidQt/¨
TWY_Wh/Y jg|W|)Y>jgtpmyhdQXZ|WbaY/izYb oZdQ_2iTWYUq)dQlW_W}Wjgtpodg@izTWYUlW_W`adQ_Zdg)iTWYV'BJs`1u _q¡jgbabem/¨
jg_W} ` i`emtzY/|Wbe`ah>jiY}X_ i`aXZYm¨BdQ_WhYZ dQtcY>jkh~T dg'izTWYqWjgbebam j 6¨Y39J
pffRpS_<« 7 i
Z\[{]Z\^
gB`efglWtzYc[ cySUTWY lW_W`adQ_
DQ
z m j z j<m D
«ySUTY hlWtwQYS@h/dQ_Wmz`ampizm.dgj-|@dQtwi`adQ_PiTWjki
q@Y/bedQ_fQm¢id j D
jk_W}<dg#jg_WdgizTWYt¢|@dQtwi`adQ_.TW`ah~T©`em h/dQ_ i~jg`a_WY}©`a_©jP}W`aTWY}WtzjgbmpYh/izdQt
dgjk_WfQbaY beY/mzm.iT¡jg_
1
_<«
dQbebad.mizT¡jkiiTWYlW_W`adQ_ dk.jgbabuizTWYq¡jgbabem j z# dgt}<J pffp`du@_ T¡jgmr7l¡jg}Wtzjki`ah
hdQXZ|WbaY¦` i§o$W+U`_5/« dQtzY/dgYt/¨yjgbabiTWYq¡jgbabemhdg_7ijg`a_ iTYdQtp`efg`e_:«SUTWYl_W`edg_ dg
iTWY'<q¡jgbabamx`am.}WY|W`ah/izY}¯dQ_5gB`efglWtzY«
SUTY |tzdNdgmy`e_ gdQbagYxdg_Wbao-YbaYXZY_ i~jktpoZfQY/dQXZY/itwoZjg_W}2iztz`afQdQ_WdQXZYitpog«SUTWY.mz` ilWj
i`adQ_Z`emu}WY/|W`ehiY/}`a_3gB`afQlWtpY jk_W}«1gB`afQlWtpY }Y|W`ah/izm'j mzY/h/iz`edQ_`e_ZiTYF §|Wbejg_WY.dg
iTWY¥mp|WTWY/tzYm: j z!jg_}B j<m D
jk_W}PiTWY¢|@dQ`a_ i ¨WizTWY¥TW`afQTWY/mpi.|)dQ`e_ iUdk`a_ iY/tzmzY/h/iz`edQ_
dgizTWYcq@dglW_W}W`a_Wfmz|WTWY/tzY/m«JSUTWYc|@dQ`a_ i `am jgbempd}Y|W`ah/izY}ªdg_PgB`afQlWtpY[«
³:³,³ B DC E l 7 i,mplhY/m.izd-|WtpdgY¥iT¡ji `em'TW`efgTWYt'izT¡jg_ x m ¨mz`a_WhY¥izTWY_
@ Y¦NiY/_W}Wm2TW`afQTWY/tizT¡jg_ax m jgm'Y/beb#jg_W} |¡jgmzmpYmizTWtzdglWfQT q7o mpoNXZXZY/iztpoQ«¯SUTWY
bed#Ympix|)dQ`e_ i dg@<q)YbadQ_WfQmUid j D
jg_W}`em.h/beYjgtzb oq@Y/bed iTWYdQtz`afQ`a_:«ySUTWYci§'dDjgh/izm
idQfQYiTWY/tU|WtzdgYizT¡jkiF@XlWmpix`e_ izYtzmpYhi¥jgbab:iTYqWjgbebam.q@Yi§'Y/Y_ j D
jk_W} jm «
{8f
g`efQltzYcySUTWYclW_W`adQ_P
DQ
z m j z «¥_iTWYctz`afQT i>¨j2qWbad §lW|dg!iTWYch/Y_ iY/tzm«
^ Yi ' q)YZizTWYZ|@dg`e_ i`e_©iTY |Wbejg_WYdQ_ izTWYZXZY}W`ejg_ q`empYh/izdQtdg jg_W} x m ¨
.`aizTmzjgXZY §dQtp}W`e_WjkiY jgm x m «H4LYY:gB`afQlWtpY «6 7§_dQtp}WYtyidc|WtpdQY.iT¡jki `amJT`efQTYt
iT¡jg_*x m ¨u` i2mzlh/YmZid<|WtpdgYiT¡jki ' q@Y/bedQ_fQm-id j<m ¨umz`a_WhYiTY_ `em-DjgtwiTWY/t
jgbedg_Wf<iTWYqW`amzY/h/idgt« SUTWYi§'d©itp`jg_fQbeY/m x m ' jg_W} Zx m T¡j>gY¯Y/rNlWjgb.jg_WfQbaYm/¨
TWY_Wh/YizTWY/ojgtzYcmz`aXZ`ebejgt/« 7 iUdgbebad.m izT¡jki
x
m('
Jwx
m x m
J x m Z-
!
J
-Nuw+: ~ m / -
! p 4 |6
.TWYtpY m J m 9 D
-
« gdgtV<jg_}O jgm.fQ` QY_¯`e_iTY hdQ_WmwitplWh/iz`edQ_¬¨#YT¡j>QY
x m(' J
~A# ?1' ~ '-{u u 'K~ ' ¤ u ! '
' +M'
- ~ ! /
.TW`eh~T¯`em.mpXjkbebaYtUiTWjg_ dQtV'
! «
³:³.³ B DC H l 7 i.`em.YjgmpoizdmpYY iTWjkiUiTWYc`a_ iYtpmzY/h/i`adQ_¯dg @<jg_W}j2q¡jgbab j z
4 ! }
`86'hdQ_mz`ampim.dgjki.XZdQmwiUi§'djgtphmUdg!h/`etphbaYg¨jg_ oPdk.TW`ah~T`emUXZdQ_WdkidQ_WY `a_
jg_WfQlWbejgtJhdNdQtz}`e_¡jiYm,jgtzdQl_W}iTY §j¦`em/¨Wjg_W}iT¡jki,jg_ omplWh~Tjgtph¢`am'Y_ iz`etpYb ojgq)dQY
iTWY|Wbejg_WY/ >J ?«xY_hYizTWY`a_ iY/tzmzY/h/iz`edQ_m¥dg@<.` iT¯iTWY |Wbejg_WYq@Y/bedQ_fid j D
jg_W} j<m D
«B7 imzlh/Ym-id¯mzTWdiTWjkiizTWYmpYP`a_7izYtpmzYhi`adQ_WmjgtpYjki-j¯}W`ampijg_Wh/Y4+jki
Xdgmpi -
-
"!
tpdQXizTWYS j¦`am«r4 NYYgB`afQlWtzY«6
7§_©iTY/ |Wbjk_WY2mzY/h/i`adQ_:¨ j D
`amjlW_`aich/`etphbaYg¨!jg_W} j<m D
`amcjh/`etphbaYdk#tzjg}W`alWm
q9J$# ~$
-
jk_W}1hY/_7izYt &%udg.h/ddgtz}W`a_¡jkizYm5+\pS? /« 4L{.Yhjgbab#iTWjki-iTYhY_ izYt2dg
Z\[{]Z\^
gB`efglWtzY cKgB`afQlWtpY¥dQt µ bejg`eX g«
j<m D
T¡jgm'hdNdQtz}W`a_¡jkizYm+ p?p /«6 Y_Wh/Y +¥`am,iTWY¢TWY`afQT i.dgjitp` jg_fQbeYx.`aizTqWjgmzY
jg_W}mz`a}WYmjg_W} q )
«17 i `am.YbaYXZY_ i~jktpoidZhdgX|liY iTWjki
+rJ ~
-
u&
-
! - 4L[ 6
gdgt,dQlWt.h~TWdQ`ahYdQt jg_W} ¨WiTW`amUoN`eY/be}Wm
+HJ ! '
u1'
~$#K'
-
~$#
'
.TW`eh~T¯`em.mpXjkbebaYtUiTWjg_
!
'dQtV'
! «
³² ® ´ ® @
l
SUT¡jg_827m¥izd ¯`eh~TWj¯NT¡jgtz`at¢ dQtx|@dg`e_ i`a_WfdQli¥iTWY|WtzdQqbeY/X
iTWYulWm/«N7 in,jkmBjgbamzd |)dQ`e_ izY}dQliniT¡ji0xbedg_ tjinX`afQT iT¡j>QY#j.h/dQ_Wmwitzlh/i`adQ_.TW`eh~T
beYjg}Wmcid¯jr7l¡jg}tjkiz`ehbed#Ytq@dQl_W} jkm#YbabL« YT¡j>QY}WYtp`agY}1dQlth/dQ_Wmwitzlh/i`adQ_
`e_W}Y|)Y_W}WY/_ ib oQ«
UkU!."'.
WaYgYjg_ ¥jg_W`aYb@O#dQ`empmzdQ__¡jki>¨w0¢_W}tz^ µ ^/tz^/dW¨ ¥ba`aN`aYt¢YN`ebabeY/tzm/¨Qjghr7lWY/be`a_WY
xlWr7lWYmp_WYg¨#jg_W} ¯jgtz`aY/ipiYuN`a_WYhk«P0x_1jgbafQdQtz` iTX dgth/dQ_WmpiztzlWhi`a_WfiTYhdg_
{8f
gB`efglWtzYcKgB`afQlWtpY¥dQt µ bejg`eX [N«
gY¦T7lWbabndgj2mpY/i dgmz|WTWY/tzY/mx`a_¯}`eXZY_mz`adQ_« 2 I 2 !PVI7I ¨
ce[k)¨¬Q «
W[Y0« xY/|W|)Ym«>O'Y/#Y`amY/`e_YtuYtpXlizlW_WfQdQ_90« /mzdQ_ oN`D«<$R M <$"
$R ML ! ¨¡c ¨¬Q «
Z\[{]Z\^
Unité de recherche INRIA Sophia Antipolis
2004, route des Lucioles - B.P. 93 - 06902 Sophia Antipolis Cedex (France)
Unité de recherche INRIA Lorraine : Technopôle de Nancy-Brabois - Campus scientifique 615, rue du Jardin Botanique - B.P. 101 - 54602 Villers lès Nancy Cedex (France)
Unité de recherche INRIA Rennes : IRISA, Campus universitaire de Beaulieu - 35042 Rennes Cedex (France) Unité de recherche INRIA Rhône-Alpes : 655, avenue de l’Europe - 38330 Montbonnot St Martin (France)
Unité de recherche INRIA Rocquencourt : Domaine de Voluceau - Rocquencourt - B.P. 105 - 78153 Le Chesnay Cedex (France)
Éditeur
INRIA - Domaine de Voluceau - Rocquencourt, B.P. 105 - 78153 Le Chesnay Cedex (France)