Pulling a graph across a partition
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I am looking for the name for a particular graph property, if it has been studied, and efficient algorithms for computing it, if they exist. I realise that this may be a well known property that I am just ignorant of, in which case I apologise, and would be grateful to be set right.
The property is as follows:
Take a graph $G=(V,E)$ on $n$ vertices, where $V$ is the vertex set and $E$ is the edge set. Let me define two families of subsets of vertices, $A_i$ and $B_i$, with the relationship that $B = V setminus A$. I require that $A_0 = V$ and $A_n$ is the empty set. Each intermediate $A_i$ is obtained from $A_{I-1}$ by removing one vertex (according to some strategy). The property I care about is $max_i |{(a,b): ain A_i, bin B_i,(a,b) in E}|$, minimised over all strategies for choosing $A_1 ldots A_{n-1}$ according to the rules above.
$A_i$ and $B_i$ can be thought of as the $i$th step in a process of moving vertices of the graph from one side of a partition (the $A$ side) to the other (the $B$ side). Thus the property I am concerned with has an operational interpretation as the maximum number of edges that need to cross the partition at any one point in time as we move the graph from one side to another, minimised over all strategies for moving vertices across the partition.
Aside from computing the value of this property, an algorithm for determining the optimal strategy would also be helpful.
graph-theory graph-algorithms co.combinatorics
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up vote
1
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I am looking for the name for a particular graph property, if it has been studied, and efficient algorithms for computing it, if they exist. I realise that this may be a well known property that I am just ignorant of, in which case I apologise, and would be grateful to be set right.
The property is as follows:
Take a graph $G=(V,E)$ on $n$ vertices, where $V$ is the vertex set and $E$ is the edge set. Let me define two families of subsets of vertices, $A_i$ and $B_i$, with the relationship that $B = V setminus A$. I require that $A_0 = V$ and $A_n$ is the empty set. Each intermediate $A_i$ is obtained from $A_{I-1}$ by removing one vertex (according to some strategy). The property I care about is $max_i |{(a,b): ain A_i, bin B_i,(a,b) in E}|$, minimised over all strategies for choosing $A_1 ldots A_{n-1}$ according to the rules above.
$A_i$ and $B_i$ can be thought of as the $i$th step in a process of moving vertices of the graph from one side of a partition (the $A$ side) to the other (the $B$ side). Thus the property I am concerned with has an operational interpretation as the maximum number of edges that need to cross the partition at any one point in time as we move the graph from one side to another, minimised over all strategies for moving vertices across the partition.
Aside from computing the value of this property, an algorithm for determining the optimal strategy would also be helpful.
graph-theory graph-algorithms co.combinatorics
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I am looking for the name for a particular graph property, if it has been studied, and efficient algorithms for computing it, if they exist. I realise that this may be a well known property that I am just ignorant of, in which case I apologise, and would be grateful to be set right.
The property is as follows:
Take a graph $G=(V,E)$ on $n$ vertices, where $V$ is the vertex set and $E$ is the edge set. Let me define two families of subsets of vertices, $A_i$ and $B_i$, with the relationship that $B = V setminus A$. I require that $A_0 = V$ and $A_n$ is the empty set. Each intermediate $A_i$ is obtained from $A_{I-1}$ by removing one vertex (according to some strategy). The property I care about is $max_i |{(a,b): ain A_i, bin B_i,(a,b) in E}|$, minimised over all strategies for choosing $A_1 ldots A_{n-1}$ according to the rules above.
$A_i$ and $B_i$ can be thought of as the $i$th step in a process of moving vertices of the graph from one side of a partition (the $A$ side) to the other (the $B$ side). Thus the property I am concerned with has an operational interpretation as the maximum number of edges that need to cross the partition at any one point in time as we move the graph from one side to another, minimised over all strategies for moving vertices across the partition.
Aside from computing the value of this property, an algorithm for determining the optimal strategy would also be helpful.
graph-theory graph-algorithms co.combinatorics
I am looking for the name for a particular graph property, if it has been studied, and efficient algorithms for computing it, if they exist. I realise that this may be a well known property that I am just ignorant of, in which case I apologise, and would be grateful to be set right.
The property is as follows:
Take a graph $G=(V,E)$ on $n$ vertices, where $V$ is the vertex set and $E$ is the edge set. Let me define two families of subsets of vertices, $A_i$ and $B_i$, with the relationship that $B = V setminus A$. I require that $A_0 = V$ and $A_n$ is the empty set. Each intermediate $A_i$ is obtained from $A_{I-1}$ by removing one vertex (according to some strategy). The property I care about is $max_i |{(a,b): ain A_i, bin B_i,(a,b) in E}|$, minimised over all strategies for choosing $A_1 ldots A_{n-1}$ according to the rules above.
$A_i$ and $B_i$ can be thought of as the $i$th step in a process of moving vertices of the graph from one side of a partition (the $A$ side) to the other (the $B$ side). Thus the property I am concerned with has an operational interpretation as the maximum number of edges that need to cross the partition at any one point in time as we move the graph from one side to another, minimised over all strategies for moving vertices across the partition.
Aside from computing the value of this property, an algorithm for determining the optimal strategy would also be helpful.
graph-theory graph-algorithms co.combinatorics
graph-theory graph-algorithms co.combinatorics
asked Dec 2 at 1:51
Joe Fitzsimons
11.5k3685
11.5k3685
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What you are looking for is known as Cutwidth. The problem is NP complete and quite well studied. For example it has a $O((log n)^{3/2})$- approximation algorithm and is fixed parameter tractable when parameterized by the objective function value.
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
1
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
6
down vote
What you are looking for is known as Cutwidth. The problem is NP complete and quite well studied. For example it has a $O((log n)^{3/2})$- approximation algorithm and is fixed parameter tractable when parameterized by the objective function value.
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
1
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
add a comment |
up vote
6
down vote
What you are looking for is known as Cutwidth. The problem is NP complete and quite well studied. For example it has a $O((log n)^{3/2})$- approximation algorithm and is fixed parameter tractable when parameterized by the objective function value.
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
1
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
add a comment |
up vote
6
down vote
up vote
6
down vote
What you are looking for is known as Cutwidth. The problem is NP complete and quite well studied. For example it has a $O((log n)^{3/2})$- approximation algorithm and is fixed parameter tractable when parameterized by the objective function value.
What you are looking for is known as Cutwidth. The problem is NP complete and quite well studied. For example it has a $O((log n)^{3/2})$- approximation algorithm and is fixed parameter tractable when parameterized by the objective function value.
answered Dec 2 at 4:39
daniello
2,6461124
2,6461124
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
1
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
add a comment |
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
1
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
Thanks. That helps a lot. Do you have a reference for the approximation algorithm?
– Joe Fitzsimons
Dec 2 at 6:15
1
1
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
A paper to cite does not come to mind but it is just applying the $sqrt{log n}$ approximation for balanced cut (Arora, Rao, Vazirani) in a divide and conquer manner (find balanced cut, solve the two sides recursively, put solution to left side before the solution to the right side). Better algorithms might be known, I am not sure.
– daniello
Dec 2 at 6:30
add a comment |
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