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Questions tagged [bipartite-graphs]

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10 votes
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Maximum weight "fair" matching

I'm interested in a variant of the maximum weight matching in a graph, which I call "Maximum Fair Matching". Assume that the graph is full (i.e. $E=V\times V$), has even number of vertices, and that ...
R B's user avatar
  • 9,458
8 votes
2 answers
3k views

Complexity of counting matchings in a bipartite graph

I might be missing something obvious but I can't find references about the complexity of counting matchings (not perfect matchings) in bipartite graphs. Here is the formal problem: Input: a bipartite ...
a3nm's user avatar
  • 9,547
6 votes
1 answer
747 views

Is "two or zero" matching in a bipartite graph NP complete?

I have this problem, which I haven't seen before in the literature: given a bipartite graph and a natural number $k$, can we select at least $k$ of the edges such that each left-hand vertex is ...
James Trimble's user avatar
6 votes
0 answers
215 views

Counting matchings on 3-regular bipartite graphs

What I call a graph here allows parallel edges. Is the following problem #P-hard: INPUT: a 3-regular bipartite graph $G$ OUTPUT: the number of matchings of $G$. It is known that counting matchings ...
M.Monet's user avatar
  • 1,429
5 votes
2 answers
296 views

Complexity of "can we get a cycle by stacking directed bipartite graphs?"

Preliminaries We consider directed bipartite graphs of the form $G = (V,V',E)$, in which the nodes are partitioned into $V = \{1,\ldots,n\}$ and $V'=\{1',\ldots,n'\}$, with $|V|=|V'|=n$, and $E\...
Davide Zorzenon's user avatar
5 votes
2 answers
323 views

Efficient way to generate random planar cubic bipartite graphs

3-regular bipartite planar graphs appear in a variety of NP- / #P-complete problems. Suppose one wants to test the complexity of these problems via numerical experiments. Is there an efficient way to ...
delete000's user avatar
  • 828
5 votes
1 answer
685 views

Bipartite Graphs - Maximum subset of one partition with at most n neighbours - NP-hard?

Given: A bipartite graph G=(U,V,E) Integers n and k. Decision Problem: Is there a subset of U of size k that has at most n neighbours? I am trying to figure out whether this problem is NP-hard (...
Simon Razniewski's user avatar
5 votes
1 answer
340 views

Sparser Bipartite graphs?

Maximal Planar Bipartite graphs are sparser than maximal planar graphs. For which other classes of graphs are maximal Bipartite members sparser than arbitrary maximal members. Let $\mathcal{C}$ be a ...
SamiD's user avatar
  • 2,319
5 votes
1 answer
2k views

Assignment problem with multiple workers for each job

I am wondering if there are any results on the following version of the assignment problem. We are given a set of jobs $J$ and a set of workers $W$, and for each job $j$ and worker $w$ we are given ...
George Octavian Rabanca's user avatar
4 votes
1 answer
73 views

Complexity of maximum k-edge-colorable subgraph of a bipartite graph

Can the maximum $k$-edge-colorable subgraph of a bipartite graph be found in polynomial time? Equivalently, can the maximum $k$-colorable subgraph of the line graph of a bipartite graph be found in ...
Timothy Chow's user avatar
  • 7,560
4 votes
1 answer
398 views

Is Permanent $+$-reducible?

Suppose we have two bipartite graphs $G_1$ and $G_2$ with perfect matching count $P_1$ and $P_2$ respectively then their disjoint union gives a bipartite graph with perfect matching $P_1P_2$. Is ...
Turbo's user avatar
  • 13k
4 votes
1 answer
767 views

Constrained version of vertex cover in a bipartite graph

Let $G(V_1, V_2, E)$ be a bipartite graph such that degree of all the vertices in $V_1$ is bounded by some constant (say) $d$. Now, for given two positive integer $l$ and $k$, we wish to decide if ...
Ram's user avatar
  • 639
4 votes
0 answers
1k views

Generating a random connected bipartite graph

A (n, m, k)-bipartite graph is a bipartite graphs with: independent sets of size $\{n, m\}$ a total of $k \geq n+m-1$ edges We want an algorithm to generate a (n, m, k)-bipartite selected uniformly ...
cglacet's user avatar
  • 141
3 votes
1 answer
170 views

Connected dominating set in bipartite graphs

Let $G$ a bipartite graph with two disjoint set of vertices $\mathbf{A}$ and $\mathbf{B}$. Denote $n_a:=|\mathbf{A}|$, $n_b:=|\mathbf{B}|$. Suppose the following conditions hold: $\Theta(1)<n_b<...
Mingzhou Liu's user avatar
3 votes
1 answer
145 views

Minimal clique edge cover vs minimalist (assignment-minimum) ones

Given a graph $G=(V,E)$, a clique edge cover is a collection $C$ of subsets of $V$ such that each element $c$ of $C$ is a clique ($c \times c \subseteq E$) and $G$ is the union of these cliques ($E = \...
Matthieu Latapy's user avatar
3 votes
0 answers
144 views

On perm+1 and det+1

Given a balanced bipartite graph G and a planar graph H. We do not know the number of perfect matchings in G and we do not know the number of spanning trees in H. But assume they are at least 3 both. ...
Turbo's user avatar
  • 13k
3 votes
0 answers
1k views

Eigenvalues of adjacency matrix of a connected bipartite graph

Let $G=(V,E)$ is a connected d-regular bipartite graph with the same number of vertices on both sides of the bipartition. It's known that that the largest eigenvalue of its adjacency matrix would be d,...
Devil's user avatar
  • 419
2 votes
2 answers
104 views

Weighted bipartite matching with no-cycle constraint

Given a weighted bipartite graph, I need to find a maximum-weight matching with the following additional constraint: the residual graph of the chosen matching is not allowed to contain any cycles. By ...
user168715's user avatar
2 votes
1 answer
77 views

Covering a binary relation as a union of rectangles

Given finite sets $X$ and $Y$ and a subset $R\subset X\times Y$, I want to express $R$ as a union $R=\bigcup_{i=1}^n X_i\times Y_i$ with $n$ as small as possible. Here, each $X_i\subset X$ and $Y_i\...
Chris Culter's user avatar
2 votes
1 answer
282 views

generate a graph with fixed min cut

Is there a constructive way to generate a graph with a fixed min cut equal to $k$? One approach is to generate a random graph and then try to make edges alterations (additions, deletions, swaps) to ...
user1798883's user avatar
2 votes
1 answer
107 views

Constrained Bipartite Matching

Let $G = (X,Y,E)$ be a bipartite graph. For some $A \subseteq X$ we say that $A$ can be perfectly matched if there is a matching $M \subseteq E$ such that all vertices in $A$ are matched; that is, for ...
John's user avatar
  • 412
2 votes
1 answer
152 views

Color shifting in a bipartite graph

Assume that we have a directed bipartite graph $G = \langle L\dot\cup R, E\rangle $. Where $E$ contains directed edges only from $L$ to $R$, that is, $E\subseteq L\times R$. Assume further that the ...
bbb3321's user avatar
  • 33
2 votes
1 answer
175 views

Maximum stable matching/allocation

I checked some papers on two-side stable allocation/matching (marriage, worker/company, doctor/hospital), but has not found any literature on the following problem. Can someone point out if I missed ...
user2789928's user avatar
2 votes
0 answers
65 views

Is there a term for expander-like graphs that expand only large subsets?

I would like to find a bipartite graph $G(L, R)$ with the following properties/constraints: For every subset $S \subseteq R$ with $\bf{|S| \geq \alpha |R|}$, its neighborhood $\Gamma(S)$ satisfies $|\...
user2465561's user avatar
2 votes
0 answers
58 views

Is Finding an *Unbalanced* Biclique in Bipartite Graphs Hard?

In the balanced biclique in bipartite graphs (MBB) problem we are given a bipartite graph $G = (L,R,E), |L| = |R| = n$ and the goal is to find an induced subgraph of $G$, $G' = (L',R',E')$, with as ...
John's user avatar
  • 412
2 votes
0 answers
96 views

Alternative criterion for approximate maximum-weight perfect matching algorithms

I have asked this question in cs.stackeschange, and it was recommended to me that I asked it here. Is there any literature on approximate maximum-weight perfect matchings where the approximation ...
prsm's user avatar
  • 29
2 votes
0 answers
69 views

Degree distribution of certain subgraphs of a biregular graph

Consider a bipartite graph $G=(X,Y)$, such that the degree of a left node $x \in X$ is $l$, and the degree of a right node $y \in Y$ is $r$. The number of edges is $|E|=|X|l=|Y|r$. Pick $w$ nodes in ...
MJK's user avatar
  • 315
1 vote
2 answers
931 views

Is perfect matching for bipartite graph with no cycles unique?

Given a balanced bipartite graph that satisfies Hall's theorem (is non singular) then it shown that it has at least one perfect matching. My question is if the balanced bipartite graph is also ...
stardust's user avatar
  • 155
1 vote
1 answer
318 views

Number of stable matchings

In the stable marriage problem, is it possible to find an instance with $2^{n -1}$ stable matchings when $n$ is a power of 2 (or just even)? If yes, how? I know how to build an instance in which $2^{n/...
Keio203's user avatar
  • 113
1 vote
1 answer
147 views

Partition the edges of a bipartite graph into perfect $b$-matchings

Any $r$-regular bipartite graph can be partitioned into $r$ disjoint perfect matchings. I want to know whether a version of this extends to perfect $b$-matchings. Suppose we have a bipartite graph $G =...
Karagounis Z's user avatar
1 vote
1 answer
230 views

Total flow using minimum number of edges on a bipartite network

If I have a set of sources $S$ with total capacity $C$ and a set of sinks $T$ with the same capacity $C$, but not necessarily the same cardinality, is there an efficient way to find the minimum number ...
Luis's user avatar
  • 19
1 vote
1 answer
421 views

What is a weakly-simplicial vertex?

While studying chordal bipartite graphs, I have come across weakly simplicial vertices. I have searched for some time to understand what a weakly simplicial vertex is but I haven't succeeded. A ...
Gunelle's user avatar
  • 33
1 vote
1 answer
128 views

Is there a regular bipartite graph where the minimum cuts are trivial?

My question is: Given integers $r$ and $k$, is there an $r$-regular bipartite graph $G = L \cup R$ with $|L| = |R| = k$, which is $r$-edge connected, and such that every minimum cut is trivial? We can ...
Karagounis Z's user avatar
1 vote
1 answer
1k views

Finding a Hamiltonian cycle from perfect matching of a bipartite graph

A disjoint vertex cycle cover of G can be found by a perfect matching on the bipartite graph, H, constructed from the original graph, G, by forming two parts G (L) and its copy G(R) with original ...
Ganapati Natarajan's user avatar
1 vote
1 answer
76 views

Bipartite graph projections, with threshold

Let $G=(\top,\bot,E)$ be a bipartite graph: $E\subseteq \top\times\bot$. The projections $G_\bot = (\bot,E_\bot)$ and $G_\top = (\top,E_\top)$ of $G$ are defined as follows: two vertices are linked ...
Matthieu Latapy's user avatar
1 vote
1 answer
104 views

Algorithm for K-best NON perfect bipartite matchings

I was reading this great article: https://core.ac.uk/download/pdf/82129717.pdf It solves a generalization of the maximum sum assignment problem by finding the k best assignments and not only the best....
Labo's user avatar
  • 129
1 vote
0 answers
84 views

Development details of the Hungarian algorithm for Maximum Perfect Bipartite Matching

There are two realization forms of Hungarian algorithm. One is the original dynamic matrix, and the other is via equality subgraph. I just checked the original paper of Hungarian method by Kuhn, which ...
Shawxing Kwok's user avatar
1 vote
0 answers
360 views

Does simplex algorithm run in polynomial on Bipartite Perfect matching polytope?

It is well known that simplex algorithm runs in exponential time in worst case. However are there situations (necessary and sufficient conditions) where simplex algorithm runs in polynomial time? In ...
Turbo's user avatar
  • 13k
1 vote
0 answers
113 views

algorithms for a large submatrix / general factor / quasi-biclique problem?

Given a sparse 0/1 matrix $X$, too large to fit in memory, with $m$ rows and $n$ columns, I'm looking for an algorithm for finding a submatrix (when one exists) with maximum number of rows such that ...
DavidDLewis's user avatar
1 vote
0 answers
120 views

Algorithm for maximum bipartite matching with arriving edges?

Given a bipartite graph with fixed nodes and incrementally arriving edges, is there any efficient algorithm to compute and update the maximum matching?
Chuancong Gao's user avatar
0 votes
1 answer
213 views

What is known about counting bipartite perfect matching with average degree in $[2,3]$ and max degree $3$?

We know counting perfect matching for bipartite graphs with vertex degree $2$ is in $P$ while counting perfect matching for graphs with vertex degree $3$ is in $\#P$. We also know there are degree $3$...
Turbo's user avatar
  • 13k
0 votes
1 answer
66 views

Do such instances always admit a 3D matching?

I want to know whether the following kinds of special instances of the 3D Matching problem are ``yes" instances, i.e., admit a 3D matching. We are given 3 sets $A,B,C$ containing $m$ elements ...
ashtavakra's user avatar
0 votes
1 answer
292 views

Online/approximate weighted and capacitated bipartite matching

I wish to take a look at online/approximate weighted and capacitated bipartite matching problem. Consider $G=\{L\cup R, E\}$, $|L|=n_1$, $|R|=n_2$, $|E|=m$ and $E\subseteq L\times R$. For each $r_i\...
user2789928's user avatar
0 votes
1 answer
134 views

Complexity and Algorithm for specific Vertex Separator Problem

Given a graph $\Gamma=(V,E)$ with vertex set $V$ and edge set $E$ a $\textit{three partition}$ is decomposition of $V$ into a triple $(V_1, S, V_2)$ such that vertices of $V_1$ are only incident to ...
user69635's user avatar
0 votes
0 answers
38 views

Bipartite Matching with a Partition Constraint over the Vertices

Let $G = (X,Y,E)$ be a bipartite graph and let $X_1,\ldots,X_r$ be a partition of $X$. For some $i \in \{1,\ldots, r\}$ and $E' \subseteq E$ we say that constraint $X_i$ is covered by some $E'$ if ...
John's user avatar
  • 412
0 votes
0 answers
47 views

On a modular inverse graph construction

Given a balanced bipartite graph $G_1$ on $2n$ vertices on the condition $PM(G_1)\equiv1\bmod2$, an integer $i$ of size $\Omega(n\log n)$, can we find a balanced bipartite graph $G_2$ on $poly(n)$ ...
Turbo's user avatar
  • 13k
0 votes
0 answers
137 views

Error in TAOCP 4a on the bipartite graph constructed from a hypergraph

The first sentence on page 33 of Donald Knuth's The Art of Computer Programming (TAOCP) Vol. 4a reads: Furthermore, a hypergraph is equivalent to a bipartite graph with vertex set $V \cup E$ and ...
Dominic van der Zypen's user avatar
-1 votes
1 answer
188 views

Reducing resource allocation problem to bipartite matching

There are a set of bins, $B$ and a set of resources $R$. Each $b \in B$ is associated with a set function $Z_b(S) : 2^R \rightarrow \mathbb{R}^+$. The resource allocation problem is to find a ...
Television's user avatar
-2 votes
1 answer
320 views

3-Hitting-Set - maximum flow algorithm [closed]

so i'm currently learning for an exam and got in an exercise the following question (a loose translation): Find an Algorithm that finds the smallest U' ⊆ U that is a solution the 3 HITTING SET ...
Frederic K.'s user avatar