/*******************************************************************************
* OscaR is free software: you can redistribute it and/or modify
* the Free Software Foundation, either version 2.1 of the License, or
* (at your option) any later version.
*
* OscaR is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License  for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with OscaR.
******************************************************************************/
package oscar.examples.cp.hakank

import oscar.cp.modeling._

import oscar.cp.core._
import scala.io.Source._
import scala.math._

/*

Magic sequence problem in Oscar.

http://www.dcs.st-and.ac.uk/~ianm/CSPLib/prob/prob019/spec.html
"""
A magic sequence of length n is a sequence of integers x0 . . xn-1 between
0 and n-1, such that for all i in 0 to n-1, the number i occurs exactly xi
times in the sequence. For instance, 6,2,1,0,0,0,1,0,0,0 is a magic sequence
since 0 occurs 6 times in it, 1 occurs twice, ...
"""

@author Hakan Kjellerstrand hakank@gmail.com
http://www.hakank.org/oscar/

*/
object MagicSequence {

def main(args: Array[String]) {

val cp = CPSolver()

//
// data
//
val n = if (args.length > 0) args(0).toInt else 10;
val all_values = Array.tabulate(n)(i=> (i,CPIntVar(0 to n-1)(cp)))

//
// variables
//
val x = Array.fill(n)(CPIntVar(0 to n-1)(cp))

//
// constraints
//
var numSols = 0
cp.solve subjectTo {

cp.add(weightedSum(0 to n, x) == n)

for(i<- 0 until n) {
}

} search {

binary(x, -_.constraintDegree, _.min)
} onSolution {

println("\nSolution:")
println("x: " + x.mkString(" "))

numSols += 1

}
println(cp.start())

}

}