# Copyright 2010 Hakan Kjellerstrand hakank@bonetmail.com
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""

  toNum in Google CP Solver.

  Convert a number <-> array of int in a specific base.

  This model was created by Hakan Kjellerstrand (hakank@bonetmail.com)
  Also see my other Google CP Solver models: http://www.hakank.org/google_or_tools/

"""




from constraint_solver import pywrapcp

#
# converts a number (s) <-> an array of integers (t) in the specific base.
#
def toNum(solver, t, s, base):
    tlen = len(t)
    solver.Add(s == solver.Sum([(base**(tlen-i-1))*t[i] for i in range(tlen)]))


def main(unused_argv):
    # Create the solver.
    solver = pywrapcp.Solver('toNum test')

    # data
    n    = 4
    base = 10

    # declare variables
    x = [solver.IntVar(0,n-1, 'x%i' % i) for i in range(n)]
    y = solver.IntVar(0,10**n-1, 'y')

    #
    # constraints
    #
    # solver.Add(solver.AllDifferent([x[i] for i in range(n)]))
    solver.Add(solver.AllDifferent(x))
    # solver.Add(x[0] > 0) # just for fun

    toNum(solver, x, y, base)

    #
    # solution and search
    #
    solution = solver.Assignment()
    solution.Add([x[i] for i in range(n)])
    solution.Add(y)

    collector = solver.AllSolutionCollector(solution)
    solver.Solve(solver.Phase([x[i] for i in range(n)],
                              solver.CHOOSE_FIRST_UNBOUND,
                              solver.ASSIGN_MIN_VALUE),
                              [collector])

    num_solutions = collector.SolutionCount()
    for s in range(num_solutions):
        print "x:", [collector.Value(s, x[i]) for i in range(n)]
        print "y:", collector.Value(s, y)
        print

    print "failures:", solver.Failures()
    print "branches:", solver.Branches()
    print "WallTime:", solver.WallTime()


if __name__ == '__main__':
    main("cp sample")