141 lines
4.4 KiB
Python
141 lines
4.4 KiB
Python
# Copyright 2010-2017 Google
|
|
# 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.
|
|
|
|
from __future__ import absolute_import
|
|
from __future__ import division
|
|
from __future__ import print_function
|
|
|
|
from ortools.sat.python import cp_model
|
|
|
|
|
|
class SolutionPrinter(cp_model.CpSolverSolutionCallback):
|
|
"""Print intermediate solutions."""
|
|
|
|
def __init__(self, num_vendors, num_hours, possible_schedules,
|
|
selected_schedules, hours_stat, min_vendors):
|
|
cp_model.CpSolverSolutionCallback.__init__(self)
|
|
self.__solution_count = 0
|
|
self.__num_vendors = num_vendors
|
|
self.__num_hours = num_hours
|
|
self.__possible_schedules = possible_schedules
|
|
self.__selected_schedules = selected_schedules
|
|
self.__hours_stat = hours_stat
|
|
self.__min_vendors = min_vendors
|
|
|
|
def OnSolutionCallback(self):
|
|
self.__solution_count += 1
|
|
print ('Solution %i: ', self.__solution_count)
|
|
print(' min vendors:', self.__min_vendors)
|
|
for i in range(self.__num_vendors):
|
|
print(' - vendor %i: ' % i,
|
|
self.__possible_schedules[self.Value(self.__selected_schedules[i])])
|
|
print()
|
|
|
|
for j in range(self.__num_hours):
|
|
print(' - # workers on day%2i: ' % j, end=' ')
|
|
print(self.Value(self.__hours_stat[j]), end=' ')
|
|
print()
|
|
print()
|
|
|
|
def SolutionCount(self):
|
|
return self.__solution_count
|
|
|
|
|
|
def main():
|
|
# Create the model.
|
|
model = cp_model.CpModel()
|
|
|
|
#
|
|
# data
|
|
#
|
|
num_vendors = 9
|
|
num_hours = 10
|
|
num_work_types = 1
|
|
|
|
traffic = [100, 500, 100, 200, 320, 300, 200, 220, 300, 120]
|
|
max_traffic_per_vendor = 100
|
|
|
|
# Last columns are :
|
|
# index_of_the_schedule, sum of worked hours (per work type).
|
|
# The index is useful for branching.
|
|
possible_schedules = [[1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 8],
|
|
[1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 4],
|
|
[0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 2, 5],
|
|
[0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 3, 4],
|
|
[1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 4, 3],
|
|
[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0]]
|
|
|
|
num_possible_schedules = len(possible_schedules)
|
|
selected_schedules = []
|
|
vendors_stat = []
|
|
hours_stat = []
|
|
|
|
|
|
# Auxiliary data
|
|
min_vendors = [t // max_traffic_per_vendor for t in traffic]
|
|
all_vendors = range(num_vendors)
|
|
all_hours = range(num_hours)
|
|
|
|
#
|
|
# declare variables
|
|
#
|
|
x = {}
|
|
|
|
for v in all_vendors:
|
|
tmp = []
|
|
for h in all_hours:
|
|
x[v, h] = model.NewIntVar(0, num_work_types, 'x[%i,%i]' % (v, h))
|
|
tmp.append(x[v, h])
|
|
selected_schedule = model.NewIntVar(0, num_possible_schedules - 1,
|
|
's[%i]' % v)
|
|
hours = model.NewIntVar(0, num_hours, 'h[%i]' % v)
|
|
selected_schedules.append(selected_schedule)
|
|
vendors_stat.append(hours)
|
|
tmp.append(selected_schedule)
|
|
tmp.append(hours)
|
|
|
|
model.AddAllowedAssignments(tmp, possible_schedules)
|
|
|
|
#
|
|
# Statistics and constraints for each hour
|
|
#
|
|
for h in all_hours:
|
|
workers = model.NewIntVar(0, 1000, 'workers[%i]' %h)
|
|
model.Add(workers == sum(x[v, h] for v in all_vendors))
|
|
hours_stat.append(workers)
|
|
model.Add(workers * max_traffic_per_vendor >= traffic[h])
|
|
|
|
#
|
|
# Redundant constraint: sort selected_schedules
|
|
#
|
|
for v in range(num_vendors - 1):
|
|
model.Add(selected_schedules[v] <= selected_schedules[v + 1])
|
|
|
|
# Solve model.
|
|
solver = cp_model.CpSolver()
|
|
solution_printer = SolutionPrinter(num_vendors, num_hours, possible_schedules,
|
|
selected_schedules, hours_stat,
|
|
min_vendors)
|
|
status = solver.SearchForAllSolutions(model, solution_printer)
|
|
print('Status = %s' % solver.StatusName(status))
|
|
|
|
print('Statistics')
|
|
print(' - conflicts : %i' % solver.NumConflicts())
|
|
print(' - branches : %i' % solver.NumBranches())
|
|
print(' - wall time : %f s' % solver.WallTime())
|
|
print(' - number of solutions found: %i' % solution_printer.SolutionCount())
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|