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# Copyright 2011 Hakan Kjellerstrand hakank@gmail.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.
"""

  Volsay problem in Google or-tools.

  From the OPL model volsay.mod

  This model was created by Hakan Kjellerstrand (hakank@gmail.com)
  Also see my other Google CP Solver models:
  http://www.hakank.org/google_or_tools/
"""
from __future__ import print_function
from ortools.linear_solver import pywraplp



# Create the solver.

# using GLPK
#solver = pywraplp.Solver('CoinsGridGLPK',
#                         pywraplp.Solver.GLPK_LINEAR_PROGRAMMING)

# Using CLP
solver = pywraplp.Solver('CoinsGridCLP',
                         pywraplp.Solver.CLP_LINEAR_PROGRAMMING)

# data

# declare variables
Gas = solver.NumVar(0, 100000, 'Gas')
Chloride = solver.NumVar(0, 100000, 'Cloride')

#
# constraints
#
solver.Add(Gas + Chloride <= 50)
solver.Add(3 * Gas + 4 * Chloride <= 180)

# objective
objective = solver.Maximize(40 * Gas + 50 * Chloride)

print('NumConstraints:', solver.NumConstraints())

#
# solution and search
#
solver.Solve()

print()
print('objective = ', solver.Objective().Value())
print('Gas = ', Gas.SolutionValue(), 'ReducedCost =', Gas.ReducedCost())
print('Chloride:', Chloride.SolutionValue(), 'ReducedCost =',
      Chloride.ReducedCost())