52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
# Copyright 2010-2013 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.
|
|
|
|
"""Magic sequence problem.
|
|
|
|
This models aims at building a sequence of numbers such that the number of
|
|
occurrences of i in this sequence is equal to the value of the ith number.
|
|
It uses an aggregated formulation of the count expression called
|
|
distribute().
|
|
"""
|
|
|
|
|
|
|
|
from google.apputils import app
|
|
import gflags
|
|
from ortools.constraint_solver import pywrapcp
|
|
|
|
FLAGS = gflags.FLAGS
|
|
|
|
|
|
def main(unused_argv):
|
|
# Create the solver.
|
|
solver = pywrapcp.Solver('magic sequence')
|
|
|
|
size = 100
|
|
all_values = range(0, size)
|
|
all_vars = [solver.IntVar(0, size, 'vars_%d' % i) for i in all_values]
|
|
|
|
solver.Add(solver.Distribute(all_vars, all_values, all_vars))
|
|
solver.Add(solver.Sum(all_vars) == size)
|
|
|
|
solver.NewSearch(solver.Phase(all_vars,
|
|
solver.CHOOSE_FIRST_UNBOUND,
|
|
solver.ASSIGN_MIN_VALUE))
|
|
solver.NextSolution()
|
|
print all_vars
|
|
solver.EndSearch()
|
|
|
|
|
|
if __name__ == '__main__':
|
|
app.run()
|