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# Copyright 2010 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.
"""

  xkcd problem (Knapsack)  in Google CP Solver.

  http://xkcd.com/287/

  Some amount (or none) of each dish should be ordered to give a total
  of exact 15.05


  Compare with the following models:
  * Comet: http://www.hakank.org/comet/xkcd.co
  * ECLiPSE: http://www.hakank.org/eclipse/xkcd.ecl
  * Gecode: http://www.hakank.org/gecode/xkcd.cpp
  * Gecode/R: http://www.hakank.org/gecode_r/xkcd.rb
  * MiniZinc: http://www.hakank.org/minizinc/xkcd.mzn
  * Tailor: http://www.hakank.org/minizinc/xkcd.mzn
  * SICtus: http://www.hakank.org/sicstus/xkcd.pl
  * Zinc: http://www.hakank.org/minizinc/xkcd.zinc


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



# Create the solver.
solver = pywrapcp.Solver("xkcd knapsack")

#
# data
#
num_prices = 6
# for price and total: multiplied by 100 to be able to use integers
price = [215, 275, 335, 355, 420, 580]
total = 1505

products = [
    "mixed fruit", "french fries", "side salad", "host wings",
    "mozzarella sticks", "samples place"
]

# declare variables

# how many items of each dish
x = [solver.IntVar(0, 10, "x%i" % i) for i in range(num_prices)]
z = solver.IntVar(0, 1505, "z")

#
# constraints
#
solver.Add(z == solver.Sum([x[i] * price[i] for i in range(num_prices)]))
solver.Add(z == total)

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

collector = solver.AllSolutionCollector(solution)
# collector = solver.FirstSolutionCollector(solution)
# search_log = solver.SearchLog(100, x[0])
solver.Solve(
    solver.Phase([x[i] for i in range(num_prices)], solver.INT_VAR_SIMPLE,
                 solver.ASSIGN_MIN_VALUE), [collector])

num_solutions = collector.SolutionCount()
print("num_solutions: ", num_solutions)
if num_solutions > 0:
  for s in range(num_solutions):
    print("z:", collector.Value(s, z) / 100.0)
    xval = [collector.Value(s, x[i]) for i in range(num_prices)]
    print("x:", xval)
    for i in range(num_prices):
      if xval[i] > 0:
        print(xval[i], "of", products[i], ":", price[i] / 100.0)
    print()

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

else:
  print("No solutions found")