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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.
"""

  Blending problem in Google or-tools.

  From the OPL model blending.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
import sys
from ortools.linear_solver import pywraplp



# Create the solver.

print('Solver: ', sol)

# using GLPK
if sol == 'GLPK':
  solver = pywraplp.Solver('CoinsGridGLPK',
                           pywraplp.Solver.GLPK_MIXED_INTEGER_PROGRAMMING)
else:
  # Using CBC
  solver = pywraplp.Solver('CoinsGridCBC',
                           pywraplp.Solver.CBC_MIXED_INTEGER_PROGRAMMING)

#
# data
#
NbMetals = 3
NbRaw = 2
NbScrap = 2
NbIngo = 1
Metals = list(range(NbMetals))
Raws = list(range(NbRaw))
Scraps = list(range(NbScrap))
Ingos = list(range(NbIngo))

CostMetal = [22, 10, 13]
CostRaw = [6, 5]
CostScrap = [7, 8]
CostIngo = [9]
Low = [0.05, 0.30, 0.60]
Up = [0.10, 0.40, 0.80]
PercRaw = [[0.20, 0.01], [0.05, 0], [0.05, 0.30]]
PercScrap = [[0, 0.01], [0.60, 0], [0.40, 0.70]]
PercIngo = [[0.10], [0.45], [0.45]]
Alloy = 71

#
# variables
#
p = [solver.NumVar(0, solver.Infinity(), 'p[%i]' % i) for i in Metals]
r = [solver.NumVar(0, solver.Infinity(), 'r[%i]' % i) for i in Raws]
s = [solver.NumVar(0, solver.Infinity(), 's[%i]' % i) for i in Scraps]
ii = [solver.IntVar(0, solver.Infinity(), 'ii[%i]' % i) for i in Ingos]
metal = [
    solver.NumVar(Low[j] * Alloy, Up[j] * Alloy, 'metal[%i]' % j)
    for j in Metals
]

z = solver.NumVar(0, solver.Infinity(), 'z')

#
# constraints
#

solver.Add(z == solver.Sum([CostMetal[i] * p[i] for i in Metals]) +
           solver.Sum([CostRaw[i] * r[i] for i in Raws]) +
           solver.Sum([CostScrap[i] * s[i] for i in Scraps]) +
           solver.Sum([CostIngo[i] * ii[i] for i in Ingos]))

for j in Metals:
  solver.Add(
      metal[j] == p[j] + solver.Sum([PercRaw[j][k] * r[k] for k in Raws]) +
      solver.Sum([PercScrap[j][k] * s[k] for k in Scraps]) +
      solver.Sum([PercIngo[j][k] * ii[k] for k in Ingos]))

solver.Add(solver.Sum(metal) == Alloy)

objective = solver.Minimize(z)

#
# solution and search
#
solver.Solve()

print()

print('z = ', solver.Objective().Value())
print('Metals')
for i in Metals:
  print(p[i].SolutionValue(), end=' ')
print()

print('Raws')
for i in Raws:
  print(r[i].SolutionValue(), end=' ')
print()

print('Scraps')
for i in Scraps:
  print(s[i].SolutionValue(), end=' ')
print()

print('Ingos')
for i in Ingos:
  print(ii[i].SolutionValue(), end=' ')
print()

print('Metals')
for i in Metals:
  print(metal[i].SolutionValue(), end=' ')
print()

print()

print('walltime  :', solver.WallTime(), 'ms')
if sol == 'CBC':
  print('iterations:', solver.Iterations())