[gecode-users] constraint “each value in array appears at least k times”

[Christian Schulte]

Please read in MPG about the global cardinality constraint (which in Gecode is also called count). It is exactly what you are looking for.

 

Best

Christian

 

--

Christian Schulte, www.gecode.org/~schulte <http://www.gecode.org/~schulte> 

Professor of Computer Science, KTH, cschulte at kth.se <mailto:cschulte at kth.se> 

Expert Researcher, SICS, cschulte at sics.se

 

From: users-bounces at gecode.org [mailto:users-bounces at gecode.org] On Behalf Of ?????? ???????
Sent: Saturday, January 28, 2017 16:02
To: users at gecode.org
Subject: [gecode-users] constraint “each value in array appears at least k times”

 

I have an IntVarArgs value of length n and I want to push a constraint that each value in array appears at least k times (or 0) f.e array [1, 2, 3, 1, 2, 3, 4, 4, 4] satisfies this constraint with k = 2

what I do now is

for (int i = 0; i < n; i++)
{
    count(*this, a, a[i], IRT_GQ, k);
}  

However, as n grows, the number of constraints grows, but I feel like it could be expressed by a single constraint. I also think that closure of array to itself is not optimal for the solver.

Is there any other solutions for this?

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