User xskxzr

29 votes

Accepted

Recover a set with the information of the sums of all its subsets

algorithms sets

answered Aug 2, 2021 at 8:26

11 votes

Accepted

Is {a^n (a+b)^n | n>0} a Deterministic CFL?

answered Mar 24, 2018 at 12:04

10 votes

Accepted

What algorithm should I use to find a minimal tree that include certain nodes within a graph?

algorithms graphs trees

answered Jul 9, 2018 at 11:09

8 votes

Under what conditions does the function C = f(A,B) satisfy H(C|A) = H(B)?

information-theory

answered Mar 28, 2019 at 8:38

7 votes

Accepted

Finding the smallest string that contains a given set of substrings

algorithms strings substrings

answered Feb 21, 2018 at 14:10

7 votes

Prove that "Finishing the degree in three years" problem is NP-Complete

complexity-theory np-complete reductions clique

answered May 12, 2019 at 8:39

6 votes

Accepted

Worst-case input for median-of-medians with groups of size 3

algorithm-analysis recursion open-problem

answered Apr 13, 2019 at 4:18

6 votes

Accepted

Is Knapsack restricted to integers between 1 and 100 still NP-complete?

algorithms complexity-theory

answered Feb 22, 2020 at 2:44

6 votes

Accepted

Empty intersection of longest path in connected graph

graphs discrete-mathematics

answered Apr 17, 2018 at 9:23

6 votes

Does adding S->SS in a context-free grammar change the language to its Kleene star?

formal-languages context-free formal-grammars kleene-star

answered Jun 14, 2018 at 6:46

5 votes

Accepted

Is it NP complete to decide whether a graph has $k$ disjoint triangles?

complexity-theory np-complete reductions np-hard decision-problem

answered May 12, 2018 at 15:51

5 votes

Accepted

Graph where only two vertices have the same degree

graphs

answered Jan 21, 2018 at 2:47

5 votes

Accepted

How to maximize $(h[j]-h[i])(j-i)$ in $O(n)$

algorithms algorithm-analysis optimization

answered Feb 7, 2018 at 13:09

5 votes

How to reduce 3-COLOR to 42-COLOR?

graphs np-complete reductions colorings

answered Dec 16, 2018 at 14:55

5 votes

Accepted

Vertex cover with covering radius 2

complexity-theory graphs np-complete np-hard vertex-cover

answered Sep 15, 2018 at 7:50

5 votes

Accepted

Prove that the 2-approximation of a modified local search algorithm for max-cut is tight

algorithms algorithm-analysis np-complete approximation max-cut

answered Dec 21, 2019 at 4:02

4 votes

Accepted

find the union of all min cuts of a flow network

algorithms graphs network-flow minimum-cuts

answered Dec 22, 2019 at 3:35

4 votes

Accepted

Are weakly polynomial time algorithms truly polynomial?

algorithms complexity-theory turing-machines computation-models

answered Feb 26, 2020 at 2:22

4 votes

Accepted

In a DAG, finding the path with the highest score

algorithms graphs graph-traversal weighted-graphs dag

answered Mar 13, 2020 at 3:15

4 votes

How to give a context-sensitive grammar for a^nba^nba^nb?

formal-languages formal-grammars context-sensitive

answered Jun 21, 2019 at 7:06

4 votes

Accepted

Finding a negative cycle in a bipartite graph

algorithms graphs shortest-path

answered Apr 5, 2019 at 13:10

4 votes

Accepted

Is DFA and Regular Expression equivalent?

formal-languages regular-languages finite-automata regular-expressions

answered Aug 24, 2018 at 9:57

4 votes

Accepted

Create a grammar that generate the language a^n . b^m . c^q . d^p such that n + p = q + m

formal-languages context-free formal-grammars

answered Mar 7, 2019 at 12:07

4 votes

Accepted

Checking if there is a single path that visits all nodes in a directed graph

graphs

answered Feb 21, 2018 at 3:57

4 votes

Show a TM-recognizable language of TMs can be expressed by TM-description language of equivalent TMs

turing-machines computability decision-problem

answered Mar 11, 2018 at 7:31

4 votes

Accepted

Time complexity of computing binomial coefficients (with binary representation of integers)

algorithms time-complexity

answered Mar 14, 2018 at 3:50

4 votes

Accepted

Union-Find with link-by-rank to represent a binary field with simple operations

data-structures union-find

answered Mar 18, 2018 at 3:22

4 votes

Accepted

Is it NP hard to partition a graph into 2 vertex sets with minimum degree of 2 and 3?

complexity-theory np-complete reductions np-hard

answered May 21, 2018 at 9:11

4 votes

Is there any language that can be Turing-reduced to all languages?

turing-machines reductions

answered Apr 8, 2018 at 3:48

3 votes

Accepted

Halting problem for polynomial space bounded Turing machines

computability undecidability

answered Apr 17, 2018 at 17:24

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239 Answers

Recover a set with the information of the sums of all its subsets

Is {a^n (a+b)^n | n>0} a Deterministic CFL?

What algorithm should I use to find a minimal tree that include certain nodes within a graph?

Under what conditions does the function C = f(A,B) satisfy H(C|A) = H(B)?

Finding the smallest string that contains a given set of substrings

Prove that "Finishing the degree in three years" problem is NP-Complete

Worst-case input for median-of-medians with groups of size 3

Is Knapsack restricted to integers between 1 and 100 still NP-complete?

Empty intersection of longest path in connected graph

Does adding S->SS in a context-free grammar change the language to its Kleene star?

Is it NP complete to decide whether a graph has $k$ disjoint triangles?

Graph where only two vertices have the same degree

How to maximize $(h[j]-h[i])(j-i)$ in $O(n)$

How to reduce 3-COLOR to 42-COLOR?

Vertex cover with covering radius 2

Prove that the 2-approximation of a modified local search algorithm for max-cut is tight

find the union of all min cuts of a flow network

Are weakly polynomial time algorithms truly polynomial?

In a DAG, finding the path with the highest score

How to give a context-sensitive grammar for a^nba^nba^nb?

Finding a negative cycle in a bipartite graph

Is DFA and Regular Expression equivalent?

Create a grammar that generate the language a^n . b^m . c^q . d^p such that n + p = q + m

Checking if there is a single path that visits all nodes in a directed graph

Show a TM-recognizable language of TMs can be expressed by TM-description language of equivalent TMs

Time complexity of computing binomial coefficients (with binary representation of integers)

Union-Find with link-by-rank to represent a binary field with simple operations

Is it NP hard to partition a graph into 2 vertex sets with minimum degree of 2 and 3?

Is there any language that can be Turing-reduced to all languages?

Halting problem for polynomial space bounded Turing machines