javax.constraints.impl.selector.VarRealSelectorMinSize Maven / Gradle / Ivy
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JCP Standard JSR331 “Java Constraint Programming API”. It is used for Modeling and Solving Constraint Satisfaction and Optimization Problems using Java and off-the-shelf Constraint/Linear Solvers
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//=============================================
// J A V A C O M M U N I T Y P R O C E S S
//
// J S R 3 3 1
//
// Common Implementation
//
//=============================================
package javax.constraints.impl.selector;
/**
* This class creates a selector that selects an unbound constrained
* real variable from a given array of real variables that has the minimal domain size.
*/
import javax.constraints.VarReal;
public class VarRealSelectorMinSize extends VarRealSelectorImpl {
/**
* Constructor from the VarReal[]
*/
public VarRealSelectorMinSize(VarReal[] vars) {
super(vars);
}
/**
* Returns the index of the unbound real variable with the smallest domain.
* If no variables to select, it returns -1;
*/
public int select() {
double minSize = Double.MAX_VALUE;
int minIndex = -1;
for(int i=0; i < getVarReals().length; i++) {
VarReal var = getVarReals()[i];
if (var.isBound())
continue;
double size = var.getMax() - var.getMin() + 1;
if (minIndex == -1 || minSize > size) {
minIndex = i;
minSize = size;
}
}
return minIndex;
}
}