# Questions tagged [cc.complexity-theory]

P versus NP and other resource-bounded computation.

2,712 questions
Filter by
Sorted by
Tagged with
53 views

### Hardness of maximizing difference of functions [closed]

Suppose that the problem of maximizing a real function $f$ over a certain domain $D$ is NP-HARD but maximizing $f-g$, with $g$ being another function over $D$, is easy (in PTIME). What can be said ...
55 views

### Has it been proved for any computational problem that it isn't in P? [closed]

i.e. are there any computable problems that are definitely not in P? Even if it's ridiculous to think that it would be in P, are there proofs of this for any algorithm? For example computing the ...
46 views

### Common solutions to 3SAT and 2SAT models comprised of the same variables

I have a problem which is a combination of 3SAT & 2SAT instances. Consider $L$ is a set of variables $(x_1 ... x_n)$. $S_3(L)$ is a 3-SAT instance and $S_2(L)$ is a 2SAT instance, both made of ...
124 views

### Isomorphism of ‘ordered’ DAGs / acyclic semiautomata

I am wondering what is known about the isomorphism problem on ordered DAGs, in particular how to find a canonical representative modulo isomorphism. By ordered I mean that each vertex has a list of ...
78 views

### Separating QMA and QCMA

A separation between $QMA$ and $QCMA$ remains a notoriously difficult open problem. Even an oracle separation remains elusive. Have there been any recent efforts towards establishing such a separation,...
40 views

### Complement of Multi-colored Clique with an extra condition

In the problem Multi-colored clique, we ask for a $k$-clique of the input graph $G$ where $G$ is guaranteed to be $k$-colorable. In the complement problem Independent Set given Clique Partition, we ...
77 views

### Complexity of Multi-colored Clique when every color pair induce biclique+isolated vertices

I am interested in the MulitColoredClique problem with an additional restriction. (Def.: A $k$-coloring $V_1,V_2,\dots,V_k$ of a graph $G$ is a partition of the vertex set of $G$ into $k$ independent ...
99 views

### Computational complexity of finding paths with specified product in a (group-labeled) directed graph

This question came up in the analysis of the puzzle game Swish. One way of representing the solvability problem is this: given a directed graph $G$ where each edge of the graph is labeled with an ...
167 views

### Why is the reduction from 3-SAT to 3-dimensional Matching Parsimonious?

In this talk at the Simons Institute, Holger Dell notes that there is a parsimonious reduction from 3-SAT to the 3-dimensional Matching (3-DM) problem. In other words, there is a reduction between ...
62 views

### Can the theory of Bidimensionality be applied to weighted instances of a problem?

So my understanding of bidimensionality is you are assured the problem solution is about O(k^2) so you can pay O(k) purely to reduce the instance to one of bounded treewidth. As far as I know, this ...
68 views

### Consequences of turning $\oplus \text{SAT}$ into few satisfying assignments

Suppose there is a reduction which, given a $\oplus \text{SAT}$ instance $\phi$, returns another $\oplus \text{SAT}$ instance $\psi$ having all the following properties: The size of $\psi$ is ...
63 views

### tables of reductions in literature [closed]

I'm interested in tables of which problems are reducible to which other problems. Particularly for graph problems, but any such tables/graphs would be neat, just so I know how to look for them. ...
177 views

### Disproving $\oplus$ETH by reducing $\oplus k$-SAT with $n$ variables and $m$ clauses to planar graph with $o(m^2)$ vertices?

In this question and its answer, they discuss about reducing CNF-SAT with $n$ variables and $m$ clauses to a (problem on) planar graph $G=(V,E)$ with $|V|$ as small as possible. It is said that the ...
79 views

### Counting on grid graphs

Are there problems defined on graphs, such as counting 2-factors, Hamiltonian cycles, connected spanning subgraphs etc., that are in $\#P$ and remain hard for grid graphs? Since there seem to be ...
5k views

### Implications of proving NP=RP on complexity theory

Edit: As indicated below by Mahdi Cheraghchi and in the comments, the paper has been withdrawn. Thanks for the multiple excellent answers on the implications of this claim. I, and hopefully others, ...
48 views

### The Edge Cover Equilibrium Problem

Let the Edge Cover Equilibrium Problem be the following: INPUT: a simple undirected graph $G$. OUTPUT: YES, if the number of edge covers of $G$ having odd cardinality is equal to the number of edge ...
83 views

82 views

### Choosing one number from each set so that the sum of squares of each distinct number counts is minimized

Problem is as follows: We are given $K$ subsets of $\{1,2,...,n\}$. We need to pick one number from each of these subsets such that $\sum_{i=1}^n p_i^2$ is minimized where $p_i$ is the number of times ...
142 views

### Adjective for: algorithm that outputs its input if it is one of its outputs?

Is there a well established adjective or name for an algorithm such that, given as input any of its own output, always outputs it unchanged? In other words, an algorithm such that it implements a ...
$ASP$-complete reductions, introduced by Ueda and Nagao, relate the hardness of computational problems in $FNP$. Basically, $ASP$-reduction is a polynomial time reduction between instances and a ...