Factory (minicp 1.0 API)

java.lang.Object
- minicp.cp.Factory

public final class Factory
extends Object

Factory to create Solver, IntVar, Constraint and some modeling utility methods. Example for the n-queens problem:

 
  Solver cp = Factory.makeSolver(false);
  IntVar[] q = Factory.makeIntVarArray(cp, n, n);
  for (int i = 0; i < n; i++)
    for (int j = i + 1; j < n; j++) {
      cp.post(Factory.notEqual(q[i], q[j]));
      cp.post(Factory.notEqual(q[i], q[j], j - i));
      cp.post(Factory.notEqual(q[i], q[j], i - j));
    }
  search.onSolution(() ->
    System.out.println("solution:" + Arrays.toString(q))
  );
  DFSearch search = Factory.makeDfs(cp,firstFail(q));
  SearchStatistics stats = search.solve();

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static IntVar`	`abs(IntVar x)` Computes a variable that is the absolute value of the given variable.
`static Constraint`	`allDifferent(IntVar[] x)` Returns a binary decomposition of the allDifferent constraint.
`static Constraint`	`allDifferentAC(IntVar[] x)` Returns an allDifferent constraint that enforces global arc consistency.
`static IntVar`	`element(int[][] matrix, IntVar x, IntVar y)` Returns a variable representing the value in a matrix at the position specified by the two given row and column index variables This relation is enforced by the `Element2D` constraint posted by calling this method.
`static IntVar`	`element(int[] array, IntVar y)` Returns a variable representing the value in an array at the position specified by the given index variable This relation is enforced by the `Element1D` constraint posted by calling this method.
`static void`	`equal(IntVar x, int v)` Forces the variable to be equal to some given value and computes the fix point.
`static BoolVar`	`isEqual(IntVar x, int c)` Returns a boolean variable representing whether one variable is equal to the given constant.
`static BoolVar`	`isLarger(IntVar x, int c)` Returns a boolean variable representing whether one variable is larger than the given constant.
`static BoolVar`	`isLargerOrEqual(IntVar x, int c)` Returns a boolean variable representing whether one variable is larger or equal to the given constant.
`static BoolVar`	`isLess(IntVar x, int c)` Returns a boolean variable representing whether one variable is less than the given constant.
`static BoolVar`	`isLessOrEqual(IntVar x, int c)` Returns a boolean variable representing whether one variable is less or equal to the given constant.
`static Constraint`	`largerOrEqual(IntVar x, IntVar y)` Returns a constraint imposing that the a first variable is larger or equal to a second one.
`static void`	`lessOrEqual(IntVar x, int v)` Forces the variable to be less or equal to some given value and computes the fix point.
`static Constraint`	`lessOrEqual(IntVar x, IntVar y)` Returns a constraint imposing that the a first variable is less or equal to a second one.
`static BoolVar`	`makeBoolVar(Solver cp)` Creates a boolean variable.
`static DFSearch`	`makeDfs(Solver cp, Supplier<Procedure[]> branching)` Creates a Depth First Search with custom branching heuristic // Example of binary search: At each node it selects // the first free variable qi from the array q, // and creates two branches qi=v, qi!
`static IntVar`	`makeIntVar(Solver cp, int sz)` Creates a variable with a domain of specified arity.
`static IntVar`	`makeIntVar(Solver cp, int min, int max)` Creates a variable with a domain equal to the specified range.
`static IntVar`	`makeIntVar(Solver cp, Set<Integer> values)` Creates a variable with a domain equal to the specified set of values.
`static IntVar[]`	`makeIntVarArray(int n, Function<Integer,IntVar> body)` Creates an array of variables with specified lambda function
`static IntVar[]`	`makeIntVarArray(Solver cp, int n, int sz)` Creates an array of variables with specified domain size.
`static IntVar[]`	`makeIntVarArray(Solver cp, int n, int min, int max)` Creates an array of variables with specified domain bounds.
`static Solver`	`makeSolver()` Creates a constraint programming solver
`static Solver`	`makeSolver(boolean byCopy)` Creates a constraint programming solver
`static IntVar`	`maximum(IntVar... x)` Computes a variable that is the maximum of a set of variables.
`static IntVar`	`minimum(IntVar... x)` Computes a variable that is the minimum of a set of variables.
`static IntVar`	`minus(IntVar x)` A variable that is a view of `-x`.
`static IntVar`	`minus(IntVar x, int v)` A variable that is a view of `x-v`.
`static IntVar`	`mul(IntVar x, int a)` A variable that is a view of `x*a`.
`static void`	`notEqual(IntVar x, int v)` Forces the variable to be different to some given value and computes the fix point.
`static Constraint`	`notEqual(IntVar x, IntVar y)` Returns a constraint imposing that the two different variables must take different values.
`static Constraint`	`notEqual(IntVar x, IntVar y, int c)` Returns a constraint imposing that the the first variable differs from the second one minus a constant value.
`static IntVar`	`plus(IntVar x, int v)` A variable that is a view of `x+v`.
`static IntVar`	`sum(IntVar... x)` Returns a variable representing the sum of a given set of variables.
`static Constraint`	`sum(IntVar[] x, int y)` Returns a sum constraint.
`static Constraint`	`sum(IntVar[] x, IntVar y)` Returns a sum constraint.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - makeSolver
```
public static Solver makeSolver()
```
    Creates a constraint programming solver
    
    Returns:
    
    a constraint programming solver with trail-based memory management
  - makeSolver
```
public static Solver makeSolver(boolean byCopy)
```
    Creates a constraint programming solver
    
    Parameters:
    
    byCopy - a value that should be true to specify copy-based state management or falso for a trail-based memory management
    
    Returns:
    
    a constraint programming solver
  - makeIntVar
```
public static IntVar makeIntVar(Solver cp,
                                int sz)
```
    Creates a variable with a domain of specified arity.
    
    Parameters:
    
    cp - the solver in which the variable is created
    
    sz - a positive value that is the size of the domain
    
    Returns:
    
    a variable with domain equal to the set {0,...,sz-1}
  - makeIntVar
```
public static IntVar makeIntVar(Solver cp,
                                int min,
                                int max)
```
    Creates a variable with a domain equal to the specified range.
    
    Parameters:
    
    cp - the solver in which the variable is created
    
    min - the lower bound of the domain (included)
    
    max - the upper bound of the domain (included) max > min
    
    Returns:
    
    a variable with domain equal to the set {min,...,max}
  - makeIntVar
```
public static IntVar makeIntVar(Solver cp,
                                Set<Integer> values)
```
    Creates a variable with a domain equal to the specified set of values.
    
    Parameters:
    
    cp - the solver in which the variable is created
    
    values - a set of values
    
    Returns:
    
    a variable with domain equal to the set of values
  - makeBoolVar
```
public static BoolVar makeBoolVar(Solver cp)
```
    Creates a boolean variable.
    
    Parameters:
    
    cp - the solver in which the variable is created
    
    Returns:
    
    an uninstantiated boolean variable
  - makeIntVarArray
```
public static IntVar[] makeIntVarArray(Solver cp,
                                       int n,
                                       int sz)
```
    Creates an array of variables with specified domain size.
    
    Parameters:
    
    cp - the solver in which the variables are created
    
    n - the number of variables to create
    
    sz - a positive value that is the size of the domain
    
    Returns:
    
    an array of n variables, each with domain equal to the set {0,...,sz-1}
  - makeIntVarArray
```
public static IntVar[] makeIntVarArray(Solver cp,
                                       int n,
                                       int min,
                                       int max)
```
    Creates an array of variables with specified domain bounds.
    
    Parameters:
    
    cp - the solver in which the variables are created
    
    n - the number of variables to create
    
    min - the lower bound of the domain (included)
    
    max - the upper bound of the domain (included) max > min
    
    Returns:
    
    an array of n variables each with a domain equal to the set {min,...,max}
  - makeIntVarArray
```
public static IntVar[] makeIntVarArray(int n,
                                       Function<Integer,IntVar> body)
```
    Creates an array of variables with specified lambda function
    
    Parameters:
    
    n - the number of variables to create
    
    body - the function that given the index i in the array creates/map the corresponding IntVar
    
    Returns:
    
    an array of n variables with variable at index i generated as body.get(i)
  - makeDfs
```
public static DFSearch makeDfs(Solver cp,
                               Supplier<Procedure[]> branching)
```
    Creates a Depth First Search with custom branching heuristic
```
 // Example of binary search: At each node it selects
 // the first free variable qi from the array q,
 // and creates two branches qi=v, qi!=v where v is the min value domain
 
 DFSearch search = Factory.makeDfs(cp, () -> {
     IntVar qi = Arrays.stream(q).reduce(null, (a, b) -> b.size() > 1 && a == null ? b : a);
     if (qi == null) {
        return return EMPTY;
     } else {
        int v = qi.min();
        Procedure left = () -> equal(qi, v); // left branch
        Procedure right = () -> notEqual(qi, v); // right branch
        return branch(left, right);
     }
 });
 
 
```
    Parameters:
    
    cp - the solver that will be used for the search
    
    branching - a generator that is called at each node of the depth first search tree to generate an array of Procedure objects that will be used to commit to child nodes. It should return BranchingScheme.EMPTY whenever the current state is a solution.
    
    Returns:
    
    the depth first search object ready to execute with DFSearch.solve() or DFSearch.optimize(Objective) using the given branching scheme
    
    See Also:
    
    BranchingScheme.firstFail(IntVar...), BranchingScheme.branch(Procedure...)
  - mul
```
public static IntVar mul(IntVar x,
                         int a)
```
    A variable that is a view of x*a.
    
    Parameters:
    
    x - a variable
    
    a - a constant to multiply x with
    
    Returns:
    
    a variable that is a view of x*a
  - minus
```
public static IntVar minus(IntVar x)
```
    A variable that is a view of -x.
    
    Parameters:
    
    x - a variable
    
    Returns:
    
    a variable that is a view of -x
  - plus
```
public static IntVar plus(IntVar x,
                          int v)
```
    A variable that is a view of x+v.
    
    Parameters:
    
    x - a variable
    
    v - a value
    
    Returns:
    
    a variable that is a view of x+v
  - minus
```
public static IntVar minus(IntVar x,
                           int v)
```
    A variable that is a view of x-v.
    
    Parameters:
    
    x - a variable
    
    v - a value
    
    Returns:
    
    a variable that is a view of x-v
  - abs
```
public static IntVar abs(IntVar x)
```
    Computes a variable that is the absolute value of the given variable. This relation is enforced by the Absolute constraint posted by calling this method.
    
    Parameters:
    
    x - a variable
    
    Returns:
    
    a variable that represents the absolute value of x
  - maximum
```
public static IntVar maximum(IntVar... x)
```
    Computes a variable that is the maximum of a set of variables. This relation is enforced by the Maximum constraint posted by calling this method.
    
    Parameters:
    
    x - the variables on which to compute the maximum
    
    Returns:
    
    a variable that represents the maximum on x
    
    See Also:
    
    minimum(IntVar...)
  - minimum
```
public static IntVar minimum(IntVar... x)
```
    Computes a variable that is the minimum of a set of variables. This relation is enforced by the Maximum constraint posted by calling this method.
    
    Parameters:
    
    x - the variables on which to compute the minimum
    
    Returns:
    
    a variable that represents the minimum on x
    
    See Also:
    
    (IntVar...)
  - equal
```
public static void equal(IntVar x,
                         int v)
```
    Forces the variable to be equal to some given value and computes the fix point.
    
    Parameters:
    
    x - the variable to be assigned to v
    
    v - the value that must be assigned to x
  - lessOrEqual
```
public static void lessOrEqual(IntVar x,
                               int v)
```
    Forces the variable to be less or equal to some given value and computes the fix point.
    
    Parameters:
    
    x - the variable that is constrained bo be less or equal to v
    
    v - the value that must be the upper bound on x
  - notEqual
```
public static void notEqual(IntVar x,
                            int v)
```
    Forces the variable to be different to some given value and computes the fix point.
    
    Parameters:
    
    x - the variable that is constrained bo be different from v
    
    v - the value that must be different from x
  - notEqual
```
public static Constraint notEqual(IntVar x,
                                  IntVar y)
```
    Returns a constraint imposing that the two different variables must take different values.
    
    Parameters:
    
    x - a variable
    
    y - a variable
    
    Returns:
    
    a constraint so that x != y
  - notEqual
```
public static Constraint notEqual(IntVar x,
                                  IntVar y,
                                  int c)
```
    Returns a constraint imposing that the the first variable differs from the second one minus a constant value.
    
    Parameters:
    
    x - a variable
    
    y - a variable
    
    c - a constant
    
    Returns:
    
    a constraint so that x != y+c
  - isEqual
```
public static BoolVar isEqual(IntVar x,
                              int c)
```
    Returns a boolean variable representing whether one variable is equal to the given constant. This relation is enforced by the IsEqual constraint posted by calling this method.
    
    Parameters:
    
    x - the variable
    
    c - the constant
    
    Returns:
    
    a boolean variable that is true if and only if x takes the value c
    
    See Also:
    
    IsEqual
  - isLessOrEqual
```
public static BoolVar isLessOrEqual(IntVar x,
                                    int c)
```
    Returns a boolean variable representing whether one variable is less or equal to the given constant. This relation is enforced by the IsLessOrEqual constraint posted by calling this method.
    
    Parameters:
    
    x - the variable
    
    c - the constant
    
    Returns:
    
    a boolean variable that is true if and only if x takes a value less or equal to c
  - isLess
```
public static BoolVar isLess(IntVar x,
                             int c)
```
    Returns a boolean variable representing whether one variable is less than the given constant. This relation is enforced by the IsLessOrEqual constraint posted by calling this method.
    
    Parameters:
    
    x - the variable
    
    c - the constant
    
    Returns:
    
    a boolean variable that is true if and only if x takes a value less than c
  - isLargerOrEqual
```
public static BoolVar isLargerOrEqual(IntVar x,
                                      int c)
```
    Returns a boolean variable representing whether one variable is larger or equal to the given constant. This relation is enforced by the IsLessOrEqual constraint posted by calling this method.
    
    Parameters:
    
    x - the variable
    
    c - the constant
    
    Returns:
    
    a boolean variable that is true if and only if x takes a value larger or equal to c
  - isLarger
```
public static BoolVar isLarger(IntVar x,
                               int c)
```
    Returns a boolean variable representing whether one variable is larger than the given constant. This relation is enforced by the IsLessOrEqual constraint posted by calling this method.
    
    Parameters:
    
    x - the variable
    
    c - the constant
    
    Returns:
    
    a boolean variable that is true if and only if x takes a value larger than c
  - lessOrEqual
```
public static Constraint lessOrEqual(IntVar x,
                                     IntVar y)
```
    Returns a constraint imposing that the a first variable is less or equal to a second one.
    
    Parameters:
    
    x - a variable
    
    y - a variable
    
    Returns:
    
    a constraint so that x <= y
  - largerOrEqual
```
public static Constraint largerOrEqual(IntVar x,
                                       IntVar y)
```
    Returns a constraint imposing that the a first variable is larger or equal to a second one.
    
    Parameters:
    
    x - a variable
    
    y - a variable
    
    Returns:
    
    a constraint so that x >= y
  - element
```
public static IntVar element(int[] array,
                             IntVar y)
```
    Returns a variable representing the value in an array at the position specified by the given index variable This relation is enforced by the Element1D constraint posted by calling this method.
    
    Parameters:
    
    array - the array of values
    
    y - the variable
    
    Returns:
    
    a variable equal to array[y]
  - element
```
public static IntVar element(int[][] matrix,
                             IntVar x,
                             IntVar y)
```
    Returns a variable representing the value in a matrix at the position specified by the two given row and column index variables This relation is enforced by the Element2D constraint posted by calling this method.
    
    Parameters:
    
    matrix - the n x m 2D array of values
    
    x - the row variable with domain included in 0..n-1
    
    y - the column variable with domain included in 0..m-1
    
    Returns:
    
    a variable equal to matrix[x][y]
  - sum
```
public static IntVar sum(IntVar... x)
```
    Returns a variable representing the sum of a given set of variables. This relation is enforced by the Sum constraint posted by calling this method.
    
    Parameters:
    
    x - the n variables to sum
    
    Returns:
    
    a variable equal to x[0]+x[1]+...+x[n-1]
  - sum
```
public static Constraint sum(IntVar[] x,
                             IntVar y)
```
    Returns a sum constraint.
    
    Parameters:
    
    x - an array of variables
    
    y - a variable
    
    Returns:
    
    a constraint so that y = x[0]+x[1]+...+x[n-1]
  - sum
```
public static Constraint sum(IntVar[] x,
                             int y)
```
    Returns a sum constraint.
    
    Parameters:
    
    x - an array of variables
    
    y - a constant
    
    Returns:
    
    a constraint so that y = x[0]+x[1]+...+x[n-1]
  - allDifferent
```
public static Constraint allDifferent(IntVar[] x)
```
    Returns a binary decomposition of the allDifferent constraint.
    
    Parameters:
    
    x - an array of variables
    
    Returns:
    
    a constraint so that x[i] != x[j] for all i < j
  - allDifferentAC
```
public static Constraint allDifferentAC(IntVar[] x)
```
    Returns an allDifferent constraint that enforces global arc consistency.
    
    Parameters:
    
    x - an array of variables
    
    Returns:
    
    a constraint so that x[i] != x[j] for all i < j

Class Factory

Method Summary

Methods inherited from class java.lang.Object

Method Detail

makeSolver

makeSolver

makeIntVar

makeIntVar

makeIntVar

makeBoolVar

makeIntVarArray

makeIntVarArray

makeIntVarArray

makeDfs

mul

minus

plus

minus

abs

maximum

minimum

equal

lessOrEqual

notEqual

notEqual

notEqual

isEqual

isLessOrEqual

isLess

isLargerOrEqual

isLarger

lessOrEqual

largerOrEqual

element

element

sum

sum

sum

allDifferent

allDifferentAC