From 1ffa25152f18588b381fa9260f437f07d9a04003 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Anton=20Luka=20=C5=A0ijanec?= Date: Mon, 15 Apr 2024 10:33:24 +0200 Subject: =?UTF-8?q?=C5=A1ola?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- "\305\241ola/ds2/kolokvij1.lyx" | 1779 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 1779 insertions(+) create mode 100644 "\305\241ola/ds2/kolokvij1.lyx" (limited to 'šola/ds2/kolokvij1.lyx') diff --git "a/\305\241ola/ds2/kolokvij1.lyx" "b/\305\241ola/ds2/kolokvij1.lyx" new file mode 100644 index 0000000..2227d5e --- /dev/null +++ "b/\305\241ola/ds2/kolokvij1.lyx" @@ -0,0 +1,1779 @@ +#LyX 2.3 created this file. For more info see http://www.lyx.org/ +\lyxformat 544 +\begin_document +\begin_header +\save_transient_properties true +\origin unavailable +\textclass article +\begin_preamble +\usepackage{siunitx} +\usepackage{pgfplots} +\usepackage{listings} +\usepackage{multicol} +\sisetup{output-decimal-marker = {,}, quotient-mode=fraction, output-exponent-marker=\ensuremath{\mathrm{3}}} +\DeclareMathOperator{\g}{g} +\DeclareMathOperator{\sled}{sled} +\DeclareMathOperator{\Aut}{Aut} +\DeclareMathOperator{\Cir}{Cir} +\DeclareMathOperator{\ecc}{ecc} +\DeclareMathOperator{\rad}{rad} +\DeclareMathOperator{\diam}{diam} +\newcommand\euler{e} +\end_preamble +\use_default_options true +\begin_modules +enumitem +\end_modules +\maintain_unincluded_children false +\language slovene +\language_package default +\inputencoding auto +\fontencoding global +\font_roman "default" "default" +\font_sans "default" "default" +\font_typewriter "default" "default" +\font_math "auto" "auto" +\font_default_family default +\use_non_tex_fonts false +\font_sc false +\font_osf false +\font_sf_scale 100 100 +\font_tt_scale 100 100 +\use_microtype false +\use_dash_ligatures true +\graphics xetex +\default_output_format default +\output_sync 0 +\bibtex_command default +\index_command default +\paperfontsize default +\spacing single +\use_hyperref false +\papersize default +\use_geometry true +\use_package amsmath 1 +\use_package amssymb 1 +\use_package cancel 1 +\use_package esint 1 +\use_package mathdots 1 +\use_package mathtools 1 +\use_package mhchem 1 +\use_package stackrel 1 +\use_package stmaryrd 1 +\use_package undertilde 1 +\cite_engine basic +\cite_engine_type default +\biblio_style plain +\use_bibtopic false +\use_indices false +\paperorientation portrait +\suppress_date false +\justification false +\use_refstyle 1 +\use_minted 0 +\index Index +\shortcut idx +\color #008000 +\end_index +\leftmargin 1cm +\topmargin 1cm +\rightmargin 1cm +\bottommargin 2cm +\headheight 1cm +\headsep 1cm +\footskip 1cm +\secnumdepth 3 +\tocdepth 3 +\paragraph_separation indent +\paragraph_indentation default +\is_math_indent 0 +\math_numbering_side default +\quotes_style german +\dynamic_quotes 0 +\papercolumns 1 +\papersides 1 +\paperpagestyle default +\tracking_changes false +\output_changes false +\html_math_output 0 +\html_css_as_file 0 +\html_be_strict false +\end_header + +\begin_body + +\begin_layout Standard +\begin_inset ERT +status open + +\begin_layout Plain Layout + + +\backslash +setlength{ +\backslash +columnseprule}{0.2pt} +\backslash +begin{multicols}{2} +\end_layout + +\end_inset + + +\end_layout + +\begin_layout Standard +Največja stopnja +\begin_inset Formula $\Delta G$ +\end_inset + +, najmanjša +\begin_inset Formula $\delta G$ +\end_inset + +. +\end_layout + +\begin_layout Standard +Rokovanje: +\begin_inset Formula $\sum_{v\in VG}\deg_{G}v=2\left|EG\right|$ +\end_inset + +. +\end_layout + +\begin_layout Standard +Vsak graf ima sodo mnogo vozlišč lihe stopnje. +\end_layout + +\begin_layout Standard +Presek/unija grafov je presek/unija njunih +\begin_inset Formula $V$ +\end_inset + + in +\begin_inset Formula $E$ +\end_inset + +. +\end_layout + +\begin_layout Standard +\begin_inset Formula $G\cup H$ +\end_inset + + je disjunktna unija grafov +\begin_inset Formula $\sim$ +\end_inset + + +\begin_inset Formula $VG\cap VH=\emptyset$ +\end_inset + +. +\end_layout + +\begin_layout Standard +Komplement grafa: +\begin_inset Formula $\overline{G}$ +\end_inset + + (obratna povezanost) +\end_layout + +\begin_layout Standard +\begin_inset Formula $0\leq\left|EG\right|\leq{\left|VG\right| \choose 2}\quad\quad\quad$ +\end_inset + +Za padajoče +\begin_inset Formula $d_{i}$ +\end_inset + + velja: +\end_layout + +\begin_layout Standard +\begin_inset Formula $\left(d_{1},\dots d_{n}\right)$ +\end_inset + + graf +\begin_inset Formula $\Leftrightarrow\left(d_{2}-1,\dots,d_{d_{1}+1}-1,\dots,d_{n}\right)$ +\end_inset + + graf +\end_layout + +\begin_layout Standard +Če je +\begin_inset Formula $AG$ +\end_inset + + matrika sosednosti, +\begin_inset Formula $\left(\left(AG\right)^{n}\right)_{i,j}$ +\end_inset + + pove št. + +\begin_inset Formula $i,j-$ +\end_inset + +poti. +\end_layout + +\begin_layout Standard +\begin_inset Formula +\[ +\text{Število trikotnikov: }\frac{\sled\left(\left(AG\right)^{3}\right)}{2\cdot3} +\] + +\end_inset + + +\end_layout + +\begin_layout Paragraph +Sprehod +\end_layout + +\begin_layout Standard +je zaporedje vozlišč, ki so verižno povezana. +\end_layout + +\begin_layout Standard +Dolžina sprehoda je število prehojenih povezav. +\end_layout + +\begin_layout Standard +Sklenjen sprehod dolžine +\begin_inset Formula $k$ +\end_inset + +: +\begin_inset Formula $v_{0}=v_{k}$ +\end_inset + + +\end_layout + +\begin_layout Standard +Enostaven sprehod ima disjunktna vozlišča razen +\begin_inset Formula $\left(v_{0},v_{k}\right)$ +\end_inset + +. +\end_layout + +\begin_layout Standard +Pot v grafu: podgraf +\begin_inset Formula $P_{k}$ +\end_inset + + +\begin_inset Formula $\sim$ +\end_inset + + enostaven nesklenjen sprehod. +\end_layout + +\begin_layout Paragraph +Cikel +\end_layout + +\begin_layout Standard +podgraf, ki je enostaven sklenjen sprehod dolžine +\begin_inset Formula $>3$ +\end_inset + +. +\end_layout + +\begin_layout Standard +Če v +\begin_inset Formula $G$ +\end_inset + + +\begin_inset Formula $\exists$ +\end_inset + + dve različni +\begin_inset Formula $u,v-$ +\end_inset + +poti +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + +\begin_inset Formula $G$ +\end_inset + + premore cikel +\end_layout + +\begin_layout Standard +Sklenjen sprehod lihe dolžine +\begin_inset Formula $\in G$ +\end_inset + + +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + lih cikel +\begin_inset Formula $\in G$ +\end_inset + + +\end_layout + +\begin_layout Paragraph +Povezanost +\end_layout + +\begin_layout Standard +\begin_inset Formula $u,v$ +\end_inset + + sta v isti komponenti +\begin_inset Formula $\text{\ensuremath{\sim}}$ +\end_inset + + +\begin_inset Formula $\text{\ensuremath{\exists}}$ +\end_inset + + +\begin_inset Formula $u,v-$ +\end_inset + +pot +\end_layout + +\begin_layout Standard +Število komponent grafa: +\begin_inset Formula $\Omega G$ +\end_inset + +. + +\begin_inset Formula $G$ +\end_inset + + povezan +\begin_inset Formula $\sim\Omega G=1$ +\end_inset + + +\end_layout + +\begin_layout Standard +Komponenta je maksimalen povezan podgraf. +\end_layout + +\begin_layout Standard +Premer: +\begin_inset Formula $\diam G=\max\left\{ d_{G}\left(v,u\right);\forall v,u\in VG\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +Ekscentričnost: +\begin_inset Formula $\ecc_{G}u=max\left\{ d_{G}\left(u,x\right);\forall x\in VG\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +Polmer: +\begin_inset Formula $\rad G=\min\left\{ \ecc u;\forall u\in VG\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $\diam C_{n}=\rad C_{n}=\lfloor\frac{n}{2}\rfloor$ +\end_inset + + +\end_layout + +\begin_layout Standard +(Liha) ožina ( +\begin_inset Formula $\g G$ +\end_inset + +) je dolžina najkrajšega (lihega) cikla. +\end_layout + +\begin_layout Standard +Vsaj en od +\begin_inset Formula $G$ +\end_inset + + in +\begin_inset Formula $\overline{G}$ +\end_inset + + je povezan. +\end_layout + +\begin_layout Standard +Povezava +\begin_inset Formula $e$ +\end_inset + + je most +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + +\begin_inset Formula $\Omega\left(G-e\right)>\Omega G$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $u$ +\end_inset + + je prerezno vozlišče +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + +\begin_inset Formula $\Omega\left(G-u\right)>\Omega G$ +\end_inset + + +\end_layout + +\begin_layout Standard +Za nepovezan +\begin_inset Formula $G$ +\end_inset + + velja +\begin_inset Formula $\diam\overline{G}\leq2$ +\end_inset + + +\end_layout + +\begin_layout Paragraph +Dvodelni +\end_layout + +\begin_layout Standard +\begin_inset Formula $\sim V=A\cup B,A\cap B=\emptyset,\forall uv\in E:u\in A\oplus v\in A$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $K_{m,n}$ +\end_inset + + je poln dvodelni graf, +\begin_inset Formula $\left|A\right|=m$ +\end_inset + +, +\begin_inset Formula $\left|B\right|=n$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + dvodelen +\begin_inset Formula $\Leftrightarrow\forall$ +\end_inset + + komponenta +\begin_inset Formula $G$ +\end_inset + + dvodelna +\end_layout + +\begin_layout Standard +Pot, sod cikel, hiperkocka so dvodelni, petersenov ni. +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + dvodelen +\begin_inset Formula $\Leftrightarrow G$ +\end_inset + + ne vsebuje lihega cikla. +\end_layout + +\begin_layout Standard +Biparticija glede na parnost +\begin_inset Formula $d_{G}\left(u,x_{0}\right)$ +\end_inset + +, +\begin_inset Formula $x_{0}$ +\end_inset + + fiksen. +\end_layout + +\begin_layout Standard +Dvodelen +\begin_inset Formula $k-$ +\end_inset + +regularen, +\begin_inset Formula $\left|E\right|\ge1\Rightarrow$ +\end_inset + + +\begin_inset Formula $\left|A\right|=\left|B\right|$ +\end_inset + +. + Dokaz: +\begin_inset Formula $\sum_{u\in A}\deg u=\left|E\right|=\cancel{k}\left|A\right|=\cancel{k}\left|B\right|=\sum_{u\in B}\deg u$ +\end_inset + + +\end_layout + +\begin_layout Paragraph +Krožni +\end_layout + +\begin_layout Standard +\begin_inset Formula $\Cir\left(n,\left\{ s_{1},\dots,s_{k}\right\} \right):\left|V\right|=n,$ +\end_inset + + množica preskokov +\end_layout + +\begin_layout Standard +\begin_inset Formula $\Omega\Cir\left(n,\left\{ s,n-s\right\} \right)=\gcd\left\{ n,s\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $W_{n}$ +\end_inset + + (kolo) pa je cikel z univerzalnim vozliščem. +\end_layout + +\begin_layout Paragraph +Homomorfizem +\end_layout + +\begin_layout Standard +\begin_inset Formula $\varphi:VG\to VH$ +\end_inset + + slika povezave v povezave +\end_layout + +\begin_layout Standard +Primer: +\begin_inset Formula $K_{2}$ +\end_inset + + je homomorfna slika +\begin_inset Formula $\forall$ +\end_inset + + bipartitnega grafa. +\end_layout + +\begin_layout Standard +V povezavah in vozliščih surjektiven +\begin_inset Formula $hm\varphi$ +\end_inset + + je epimorfizem. +\end_layout + +\begin_layout Standard +V vozliščih injektiven +\begin_inset Formula $hm\varphi$ +\end_inset + + je monomorfizem/vložitev. +\end_layout + +\begin_layout Standard +Vložitev, ki ohranja razdalje, je izometrična. +\end_layout + +\begin_layout Standard +Kompozitum homomorfizmov je spet homomorfizem. +\end_layout + +\begin_layout Standard +Izomorfizem je bijektivni +\begin_inset Formula $hm\varphi$ +\end_inset + + s homomorfnim inverzom. +\end_layout + +\begin_layout Standard +\begin_inset Formula $im\varphi$ +\end_inset + + +\begin_inset Formula $f:VG\to VH$ +\end_inset + + +\begin_inset Formula $\forall u,v\in VG:uv\in EG\Leftrightarrow fufv\in EH$ +\end_inset + + +\end_layout + +\begin_layout Standard +Nad množico vseh grafov +\begin_inset Formula $\mathcal{G}$ +\end_inset + + je izomorfizem ( +\begin_inset Formula $\cong$ +\end_inset + +) ekv. + rel. +\end_layout + +\begin_layout Standard +\begin_inset Formula $im\varphi$ +\end_inset + + +\begin_inset Formula $G\to G$ +\end_inset + + je avtomorfizem. +\end_layout + +\begin_layout Standard +\begin_inset Formula $\Aut G$ +\end_inset + + je grupa avtomorfizmov s komponiranjem. +\end_layout + +\begin_layout Standard +\begin_inset Formula $\Aut K_{n}=\left\{ \pi\in S_{n}=\text{permutacije }n\text{ elementov}\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $\Aut P_{n}=\left\{ \text{trivialni }id,f\left(i\right)=n-i-1\right\} $ +\end_inset + +, +\begin_inset Formula $\Aut G\cong\Aut\overline{G}$ +\end_inset + + +\end_layout + +\begin_layout Standard +Izomorfizem ohranja stopnje, št. + +\begin_inset Formula $C_{4}$ +\end_inset + +, povezanost, +\begin_inset Formula $\left|EG\right|,\dots$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G\cong\overline{G}\Rightarrow\left|VG\right|\%4\in\left\{ 0,1\right\} $ +\end_inset + + +\end_layout + +\begin_layout Paragraph +Operacije +\end_layout + +\begin_layout Standard +\begin_inset Formula $H$ +\end_inset + + vpeti podgraf +\begin_inset Formula $G\Leftrightarrow\exists F\subseteq EG\ni:H=G-F$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $H$ +\end_inset + + inducirani podgraf +\begin_inset Formula $G\Leftrightarrow\exists S\subseteq VG\ni:H=G-S$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $H$ +\end_inset + + podgraf +\begin_inset Formula $G\Leftrightarrow\exists S\subseteq VG,F\subseteq EG\ni:H=\left(G-F\right)-S$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $uv=e\in EG$ +\end_inset + +. + +\begin_inset Formula $G/e$ +\end_inset + + je skrčitev. + (identificiramo +\begin_inset Formula $u=v$ +\end_inset + +) +\end_layout + +\begin_layout Standard +\begin_inset Formula $H$ +\end_inset + + minor +\begin_inset Formula $G$ +\end_inset + +: +\begin_inset Formula $H=f_{1}...f_{k}G$ +\end_inset + + za +\begin_inset Formula $f_{i}$ +\end_inset + + skrčitev/odstranjevanje +\end_layout + +\begin_layout Standard +\begin_inset Formula $VG^{+}e\coloneqq VG\cup\left\{ x_{e}\right\} $ +\end_inset + +, +\begin_inset Formula $EG^{+}e\coloneqq EG\setminus e\cup\left\{ x_{e}u,x_{e}v\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $VG^{+}e$ +\end_inset + + je subdivizija, +\begin_inset Formula $e\in EG$ +\end_inset + +. + Na +\begin_inset Formula $e$ +\end_inset + + dodamo vozlišče. +\end_layout + +\begin_layout Standard +\begin_inset Formula $H$ +\end_inset + + subdivizija +\begin_inset Formula $G$ +\end_inset + + +\begin_inset Formula $\Leftrightarrow H=G^{+}\left\{ e_{1},\dots,e_{k}\right\} ^{+}\left\{ f_{1}\dots f_{j}\right\} ^{+}\dots$ +\end_inset + + +\end_layout + +\begin_layout Standard +Stopnja vozlišč se s subdivizijo ne poveča. +\end_layout + +\begin_layout Standard +Glajenje +\begin_inset Formula $G^{-}v$ +\end_inset + +, +\begin_inset Formula $v\in VG$ +\end_inset + + je obrat subdivizije. + +\begin_inset Formula $\deg_{G}v=2$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + in +\begin_inset Formula $H$ +\end_inset + + sta homeomorfna, če sta subdivizija istega grafa. +\end_layout + +\begin_layout Standard +Kartezični produkt: +\begin_inset Formula $V\left(G\square H\right)\coloneqq VG\times VH$ +\end_inset + +, +\begin_inset Formula $E\left(G\square H\right)\coloneqq\left\{ \left\{ \left(g,h\right),\left(g',h'\right)\right\} ;g=g'\wedge hh'\in EH\vee h=h'\wedge gg'\in EG\right\} $ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $\left(\mathcal{G},\square\right)$ +\end_inset + + monoid, enota +\begin_inset Formula $K_{1}$ +\end_inset + +. + +\begin_inset Formula $Q_{n}\cong Q_{n-1}\square K_{2}=Q_{n-2}\square K_{2}^{\square,2}$ +\end_inset + + +\end_layout + +\begin_layout Standard +Disjunktna unija: +\begin_inset Formula $G$ +\end_inset + +, +\begin_inset Formula $H$ +\end_inset + + disjunktna. + +\begin_inset Formula $V\left(G\cup H\right)\coloneqq VG\cup VH$ +\end_inset + +, +\begin_inset Formula $E\left(G\cup H\right)\coloneqq EG\cup EH$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G,H$ +\end_inset + + dvodelna +\begin_inset Formula $\Rightarrow G\square H$ +\end_inset + + dvodelen +\end_layout + +\begin_layout Paragraph +\begin_inset Formula $k-$ +\end_inset + +povezan graf +\end_layout + +\begin_layout Standard +ima +\begin_inset Formula $\geq k+1$ +\end_inset + + vozlišč in ne vsebuje prerezne množice moči +\begin_inset Formula $\Omega G$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $Y\subseteq EG$ +\end_inset + + prerezna množica povezav +\begin_inset Formula $\Leftrightarrow\Omega\left(G-Y\right)>\Omega G$ +\end_inset + + +\end_layout + +\begin_layout Standard +Povezanost grafa: +\begin_inset Formula $\kappa G=\max k$ +\end_inset + +, da je +\begin_inset Formula $G$ +\end_inset + + +\begin_inset Formula $k-$ +\end_inset + +povezan. + Primeri: +\begin_inset Formula $\kappa K_{n}=n-1$ +\end_inset + +, +\begin_inset Formula $\kappa P_{n}=1$ +\end_inset + +, +\begin_inset Formula $\kappa C_{n}=2$ +\end_inset + +, +\begin_inset Formula $\kappa K_{n,m}=\min\left\{ n,m\right\} $ +\end_inset + +, +\begin_inset Formula $\kappa Q_{n}=n$ +\end_inset + +, +\begin_inset Formula $\kappa G\text{\ensuremath{\leq}}\delta G$ +\end_inset + + +\end_layout + +\begin_layout Standard +Izrek (Menger): +\begin_inset Formula $\left|VG\right|\geq k+1$ +\end_inset + +: +\begin_inset Formula $G$ +\end_inset + + +\begin_inset Formula $k-$ +\end_inset + +povezan +\begin_inset Formula $\Leftrightarrow\forall u,v\in VG,uv\not\in EG:\exists k$ +\end_inset + + notranje disjunktnih +\begin_inset Formula $u,v-$ +\end_inset + +poti +\end_layout + +\begin_layout Standard +Graf je +\begin_inset Formula $k-$ +\end_inset + +povezan po povezavah, če ne vsebuje prerezne množice povezav moči +\begin_inset Formula $\left|S\right|\Rightarrow G$ +\end_inset + + ni hamiltonov. + Primer: +\begin_inset Formula $G$ +\end_inset + + vsebuje prerezno vozlišče +\begin_inset Formula $\Rightarrow G$ +\end_inset + + ni hamiltonov. +\end_layout + +\begin_layout Standard +\begin_inset Formula $K_{n,m}$ +\end_inset + + je hamiltonov +\begin_inset Formula $\Leftrightarrow m=n$ +\end_inset + + (za +\begin_inset Formula $S$ +\end_inset + + vzamemo +\begin_inset Formula $\min\left\{ m,n\right\} $ +\end_inset + +) +\end_layout + +\begin_layout Standard +\begin_inset Formula $\left|VG\right|\geq3,\forall u,v\in VG:\deg_{G}u+\deg_{G}v\geq\left|VG\right|\Rightarrow G$ +\end_inset + + hamil. +\end_layout + +\begin_layout Standard +Dirac: +\begin_inset Formula $\left|VG\right|\geq3,\forall u\in VG:\deg_{G}u\geq\frac{\left|VG\right|}{2}\Rightarrow G$ +\end_inset + + hamilton. +\end_layout + +\begin_layout Paragraph +Ravninski +\end_layout + +\begin_layout Standard +graf brez sekanja povezav narišemo v ravnino +\end_layout + +\begin_layout Standard +\begin_inset Formula $K_{2,3}$ +\end_inset + + je ravninski, +\begin_inset Formula $K_{3,3}$ +\end_inset + +, +\begin_inset Formula $K_{5}$ +\end_inset + +, +\begin_inset Formula $C_{5}\square C_{5}$ +\end_inset + + in +\begin_inset Formula $P_{5,2}$ +\end_inset + + niso ravninski. +\end_layout + +\begin_layout Standard +Vložitev je ravninski graf z ustrezno risbo v ravnini. +\end_layout + +\begin_layout Standard +Lica so sklenjena območja vložitve brez vozlišč in povezav. +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + lahko vložimo v ravnino +\begin_inset Formula $\Leftrightarrow G$ +\end_inset + + lahko vložimo na sfero. +\end_layout + +\begin_layout Standard +Dolžina lica +\begin_inset Formula $F\sim lF$ +\end_inset + + je št. + povezav obhoda lica. +\end_layout + +\begin_layout Standard +Drevo je ravninski graf z enim licem dolžine +\begin_inset Formula $2\left|ET\right|$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $\sum_{F\in FG}lF=2\left|EG\right|$ +\end_inset + +, +\begin_inset Formula $lF\geq gG$ +\end_inset + + za ravninski +\begin_inset Formula $G$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $2\left|EG\right|=\sum_{F\in FG}lF\geq\sum_{F\in FG}gG=gG\left|FG\right|$ +\end_inset + + ( +\begin_inset Formula $G$ +\end_inset + + ravn.) +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + ravninski +\begin_inset Formula $\Rightarrow\left|EG\right|\geq\frac{gG}{2}$ +\end_inset + + +\begin_inset Formula $\left|FG\right|$ +\end_inset + + +\end_layout + +\begin_layout Standard +Euler: +\begin_inset Formula $\left|VG\right|-\left|EG\right|+\left|FG\right|=1+\Omega G$ +\end_inset + + za ravninski +\begin_inset Formula $G$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + ravninski, +\begin_inset Formula $\left|VG\right|\geq3\Rightarrow\left|EG\right|\leq3\left|VG\right|-6$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + ravninski brez +\begin_inset Formula $C_{3}$ +\end_inset + +, +\begin_inset Formula $\left|VG\right|\geq3\Rightarrow\left|EG\right|\text{\ensuremath{\leq2\left|VG\right|-4}}$ +\end_inset + + +\end_layout + +\begin_layout Standard +Triangulacija je taka vložitev, da so vsa lica omejena s +\begin_inset Formula $C_{3}$ +\end_inset + +. +\end_layout + +\begin_layout Standard +V maksimalen ravninski graf ne moremo dodati povezave, da bi ostal ravninski. + +\begin_inset Formula $\sim$ +\end_inset + + Ni pravi vpet podgraf ravn. + grafa. +\end_layout + +\begin_layout Standard +\begin_inset Formula $K_{5}-e$ +\end_inset + + je maksimalen ravninski graf +\begin_inset Formula $\forall e\in EK_{5}$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + ravninski. + NTSE: +\begin_inset Formula $G$ +\end_inset + + triangulacija +\begin_inset Formula $\Leftrightarrow G$ +\end_inset + + maksimalen ravninski +\begin_inset Formula $\Leftrightarrow\left|EG\right|=3\left|VG\right|-6$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset Formula $G$ +\end_inset + + ravninski +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + vsaka subdivizija +\begin_inset Formula $G$ +\end_inset + + ravninska. +\end_layout + +\begin_layout Standard +Kuratovski: +\begin_inset Formula $G$ +\end_inset + + ravn. + +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + ne vsebuje subdivizije +\begin_inset Formula $K_{5}$ +\end_inset + + ali +\begin_inset Formula $K_{3,3}$ +\end_inset + + +\end_layout + +\begin_layout Standard +Wagner: +\begin_inset Formula $G$ +\end_inset + + ravn. + +\begin_inset Formula $\Leftrightarrow$ +\end_inset + + niti +\begin_inset Formula $K_{5}$ +\end_inset + + niti +\begin_inset Formula $K_{3,3}$ +\end_inset + + nista njegova minorja +\end_layout + +\begin_layout Standard +Zunanje-ravninski ima vsa vozlišča na robu zunanjega lica. +\end_layout + +\begin_layout Standard +\begin_inset Formula $2-$ +\end_inset + +povezan zunanje-ravninski je +\series bold +hamiltonov +\series default +. +\end_layout + +\begin_layout Standard +Zunanje-ravninski +\begin_inset Formula $G$ +\end_inset + +, +\begin_inset Formula $\left|VG\right|\geq2$ +\end_inset + + ima vozlišče stopnje +\begin_inset Formula $\leq2$ +\end_inset + +. +\end_layout + +\begin_layout Paragraph +Barvanje +\end_layout + +\begin_layout Standard +je taka +\begin_inset Formula $C:VG\to\left\{ 1..k\right\} \Leftrightarrow\forall uv\in EG:Cu\not=Cv$ +\end_inset + + +\end_layout + +\begin_layout Standard +Kromatično število +\begin_inset Formula $\chi G$ +\end_inset + + je najmanjši +\begin_inset Formula $k$ +\end_inset + +, +\begin_inset Formula $\ni:\exists$ +\end_inset + + +\begin_inset Formula $k-$ +\end_inset + +barvanje +\begin_inset Formula $G$ +\end_inset + + +\end_layout + +\begin_layout Standard +Primer: +\begin_inset Formula $\chi K_{n}=n$ +\end_inset + +, +\begin_inset Formula $\chi C_{n}=\begin{cases} +2 & ;n\text{ sod}\\ +3 & ;n\text{ lih} +\end{cases}$ +\end_inset + + +\end_layout + +\begin_layout Standard +\begin_inset ERT +status open + +\begin_layout Plain Layout + + +\backslash +end{multicols} +\end_layout + +\end_inset + + +\end_layout + +\end_body +\end_document -- cgit v1.2.3