diff --git a/main.tex b/main.tex index 85137a1..459a8e4 100644 --- a/main.tex +++ b/main.tex @@ -35,8 +35,8 @@ \pause \medskip -\begin{problem}[Zenklusen ORL'14] -Let $G=(V,E)$ be a graph with edge capacity $c:E\to\mathbb{Z}_+$ and edge removal costs $w:E\to\mathbb{Z}_+$ and let $B\in \mathbb Z_+$ be the budget. +\begin{problem}[{[Zenklusen ORL'14]}] +Let $G=(V,E)$ be a graph with edge weights $w:E\to\mathbb{Z}_+$ and edge removal costs $c:E\to\mathbb{Z}_+$ and let $B\in \mathbb Z_+$ be the budget. Find $F\subset E$ with $w(F)\leq B$ s.t. the min-cut in $G-F$ is minimized. \end{problem} @@ -57,8 +57,8 @@ unit cost $w(\cdot)=1$ & general case & random? & ref \\ \midrule $O(m^2n^4\log n)$ & $O(m^{2+1/\varepsilon}n^4\log n)$ & $\times$ & [Zenklusen ORL'14] \\ $O(mn^4\log^2 n)$ & $O(m^{1+1/\varepsilon}n^4\log^2 n)$ & $\checkmark$ & [Zenklusen ORL'14] \\ -$\tilde O(m+n^4 B)$ & $O(\frac{m^2n^4}{\varepsilon}\log(Bnc_{\max}))$ & $\times$ & [C.-C. Huang et al. IPCO'24]\\ -$\tilde O(n^3m\log c_{\max})$ & - & $\checkmark$ & [Drange et al. AAAI'26]\\ +$\tilde O(m+n^4 B)$ & $O(\frac{m^2n^4}{\varepsilon}\log(Bnw_{\max}))$ & $\times$ & [C.-C. Huang et al. IPCO'24]\\ +$\tilde O(n^3m\log w_{\max})$ & - & $\checkmark$ & [Drange et al. AAAI'26]\\ $\tilde O(m^2+n^3B)$ & $\tilde O(m^2+mn^3+\frac{n^3}{\varepsilon})$ & $\times$ & this work\\ $\tilde O(m+n^3B)$ & $\tilde O(mn^3+\frac{n^3}{\varepsilon})$ & $\checkmark$ & this work\\ \bottomrule @@ -66,6 +66,31 @@ $\tilde O(m+n^3B)$ & $\tilde O(mn^3+\frac{n^3}{\varepsilon})$ & $\checkmark$ & \caption{PTASes for connectivity interdiction} \end{table} \end{frame} + +\begin{frame}{Method in [C.-C. Huang et al. IPCO'24]} +They use an intemediate problem called \emph{normalized min-cut}. +\begin{problem}[{[Chalermsook ICALP'22]}] +Given the same input as connectivity interdiction, find a cut $C$ and a subset of its edges $F\subset C$ satisfying $0\leq c(F)\leq B$, so that $\frac{w(C-F)}{B-c(F)+1}$ is minimized. +\end{problem} + +\pause\medskip +Normalized min-cut is first considered in [Chalermsook ICALP'22] as a subproblem in MWU framework when solving minimum $k$-edge connected spanning subgraph (ECSS) problem. + +\pause\medskip +... +\end{frame} + +\begin{frame}{LP method} +\begin{equation*} +\begin{aligned} +\min& & \sum_{e} x_e w(e)& & & \\ +s.t.& & \sum_{e\in T} x_e+y_e&\geq 1 & &\forall T\quad \text{($x+y$ is a cut)}\\ +& & \sum_{e} y_e c(e) &\leq B & &\text{(budget for $F$)}\\ +& & y_e,x_e&\in\{0,1\} & &\forall e +\end{aligned} +\end{equation*} +\end{frame} + \section{Computing cogirth in perturbed graphic matroids} \begin{frame}{Perturbed graphic matroids} \end{frame}