• Parameterization Above a Multiplicative Guarantee 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      Parameterization above a guarantee is a successful paradigm in Parameterized Complexity. To the best of our knowledge, all fixed-parameter tractable problems in this paradigm share an additive form defined as follows. Given ...
    • Parameterized complexity classification of deletion to list matrix-partition for low-order matrices 

      Agrawal, Akanksha; Kolay, Sudeshna; Madathil, Jayakrishnan; Saurabh, Saket (Journal article; Peer reviewed, 2019)
      Given a symmetric l x l matrix M=(m_{i,j}) with entries in {0,1,*}, a graph G and a function L : V(G) - > 2^{[l]} (where [l] = {1,2,...,l}), a list M-partition of G with respect to L is a partition of V(G) into l parts, ...
    • Parameterized complexity of conflict-free matchings and paths 

      Agrawal, Akanksha; Jain, Pallavi; Kanesh, Lawqueen; Saurabh, Saket (Journal article; Peer reviewed, 2019)
      An input to a conflict-free variant of a classical problem Gamma, called Conflict-Free Gamma, consists of an instance I of Gamma coupled with a graph H, called the conflict graph. A solution to Conflict-Free Gamma in (I,H) ...
    • Parameterized Complexity of Directed Spanner Problems 

      Fomin, Fedor; Golovach, Petr; Lochet, William; Misra, Pranabendu; Saurabh, Saket; Sharma, Roohani (Journal article; Peer reviewed, 2020)
      We initiate the parameterized complexity study of minimum t-spanner problems on directed graphs. For a positive integer t, a multiplicative t-spanner of a (directed) graph G is a spanning subgraph H such that the distance ...
    • The Parameterized Complexity of Guarding Almost Convex Polygons 

      Agrawal, Akanksha; Knudsen, Kristine Vitting Klinkby; Lokshtanov, Daniel; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      The Art Gallery problem is a fundamental visibility problem in Computational Geometry. The input consists of a simple polygon P, (possibly infinite) sets G and C of points within P, and an integer k; the task is to decide ...
    • Parameterized Single-Exponential Time Polynomial Space Algorithm for Steiner Tree 

      Fomin, Fedor; Kaski, Petteri; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket (Peer reviewed; Journal article, 2019)
      In the Steiner Tree problem, we are given as input a connected \(n\)-vertex graph with edge weights in \(\{1,2,\ldots,W\}\), and a set of \(k\) terminal vertices. Our task is to compute a minimum-weight tree that contains ...
    • Parameterized streaming algorithms for min-ones d-SAT 

      Agrawal, Akanksha; Bonnet, Édouard; Curticapean, Radu; Miltzow, Tillmann; Saurabh, Saket; Biswas, Arindam; Brettell, Nick; Marx, Dániel; Raman, Venkatesh (Journal article; Peer reviewed, 2019)
      In this work, we initiate the study of the Min-Ones d-SAT problem in the parameterized streaming model. An instance of the problem consists of a d-CNF formula F and an integer k, and the objective is to determine if F has ...
    • Path contraction faster than $2^n$ 

      Agrawal, Akanksha; Fomin, Fedor; Lokshtanov, Daniel; Saurabh, Saket; Tale, Prafullkumar (Journal article; Peer reviewed, 2020)
      A graph $G$ is contractible to a graph $H$ if there is a set $X \subseteq E(G)$, such that $G/X$ is isomorphic to $H$. Here, $G/X$ is the graph obtained from $G$ by contracting all the edges in $X$. For a family of graphs ...
    • Path Contraction Faster Than 2n 

      Agrawal, Akanksha; Fomin, Fedor; Lokshtanov, Daniel; Saurabh, Saket; Tale, Prafullkumar (Peer reviewed; Journal article, 2019)
      A graph G is contractible to a graph H if there is a set X subseteq E(G), such that G/X is isomorphic to H. Here, G/X is the graph obtained from G by contracting all the edges in X. For a family of graphs F, the F-Contraction ...
    • A Polynomial Kernel for Paw-Free Editing 

      Eiben, Eduard; Lochet, William; Saurabh, Saket (Journal article; Peer reviewed, 2020)
      For a fixed graph H, the H-free Edge Editing problem asks whether we can modify a given graph G by adding or deleting at most k edges such that the resulting graph does not contain H as an induced subgraph. The problem is ...
    • Quick but odd growth of cacti 

      Kolay, Sudeshna; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket (Conference object; Peer reviewed; Journal article, 2015)
      Let F be a family of graphs. Given an input graph G and a positive integer k, testing whether G has a k-sized subset of vertices S, such that G\S belongs to F, is a prototype vertex deletion problem. These type of problems ...
    • Quick separation in chordal and split graphs 

      Misra, Pranabendu; Panolan, Fahad; Rai, Ashutosh; Saurabh, Saket; Sharma, Roohani (Journal article; Peer reviewed, 2020)
      In this paper we study two classical cut problems, namely Multicut and Multiway Cut on chordal graphs and split graphs. In the Multicut problem, the input is a graph G, a collection of 𝓁 vertex pairs (si, ti), i ∈ [𝓁], ...
    • Rank vertex cover as a natural problem for algebraic compression 

      Meesum, Syed Mohammad; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2019)
      The question of the existence of a polynomial kernelization of the Vertex Cover Above LP problem was a long-standing, notorious open problem in parameterized complexity. Some years ago, the breakthrough work by Kratsch and ...
    • Subexponential Algorithms for Partial Cover Problems 

      Fomin, Fedor; Lokshtanov, Daniel; Raman, Venkatesh; Saurabh, Saket (Conference object; Peer reviewed; Journal article, 2009)
      Partial Cover problems are optimization versions of fundamental and well studied problems like {\sc Vertex Cover} and {\sc Dominating Set}. Here one is interested in covering (or dominating) the maximum number of edges (or ...
    • Subquadratic Kernels for Implicit 3-Hitting Set and 3-Set Packing Problems 

      Fomin, Fedor; Le, Tien-Nam; Lokshtanov, Daniel; Saurabh, Saket; Thomasse, Stephan; Zehavi, Meirav (Peer reviewed; Journal article, 2019)
      We consider four well-studied NP-complete packing/covering problems on graphs: Feedback Vertex Set in Tournaments (FVST), Cluster Vertex Deletion (CVD), Triangle Packing in Tournaments (TPT) and Induced P3-Packing. For ...