113 lines
3.7 KiB
Python
113 lines
3.7 KiB
Python
|
# Copyright 2010-2011 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.
|
||
|
|
|
||
|
|
"""
|
||
|
|
This problem has 72 different solutions in base 10.
|
||
|
|
|
||
|
|
Use of SolutionCollectors.
|
||
|
|
Use of Solve().
|
||
|
|
Use of gflags to choose the base.
|
||
|
|
Change the time limit of the solver.
|
||
|
|
"""
|
||
|
|
|
||
|
|
import gflags, sys
|
||
|
|
from constraint_solver import pywrapcp
|
||
|
|
from os import abort
|
||
|
|
|
||
|
|
FLAGS = gflags.FLAGS
|
||
|
|
gflags.DEFINE_integer('base', 10, "Base used to solve the problem.")
|
||
|
|
gflags.DEFINE_bool('print_all_solutions', False, "Print all solutions?")
|
||
|
|
gflags.DEFINE_integer('time_limit', 10000, "Time limit in milliseconds")
|
||
|
|
|
||
|
|
def CPIsFun():
|
||
|
|
# Use some profiling and change the default parameters of the solver
|
||
|
|
solver_params = pywrapcp.SolverParameters()
|
||
|
|
# Change the profile level
|
||
|
|
solver_params.profile_level = pywrapcp.SolverParameters.NORMAL_PROFILING
|
||
|
|
|
||
|
|
# Constraint programming engine
|
||
|
|
solver = pywrapcp.Solver('CP is fun!', solver_params);
|
||
|
|
|
||
|
|
kBase = gflags.FLAGS.base
|
||
|
|
|
||
|
|
# Decision variables
|
||
|
|
digits = range(0, kBase)
|
||
|
|
digits_without_zero = digits[1:]
|
||
|
|
|
||
|
|
c = solver.IntVar(digits_without_zero, 'C');
|
||
|
|
p = solver.IntVar(digits, 'P');
|
||
|
|
i = solver.IntVar(digits_without_zero, 'I');
|
||
|
|
s = solver.IntVar(digits, 'S');
|
||
|
|
f = solver.IntVar(digits_without_zero, 'F');
|
||
|
|
u = solver.IntVar(digits, 'U');
|
||
|
|
n = solver.IntVar(digits, 'N');
|
||
|
|
t = solver.IntVar(digits_without_zero, 'T');
|
||
|
|
r = solver.IntVar(digits, 'R');
|
||
|
|
e = solver.IntVar(digits, 'E');
|
||
|
|
|
||
|
|
# We need to group variables in a list to be able to use
|
||
|
|
# the global constraint AllDifferent
|
||
|
|
letters = [c, p, i, s, f, u, n, t, r, e]
|
||
|
|
|
||
|
|
# Check if we have enough digits
|
||
|
|
assert kBase >= len(letters)
|
||
|
|
|
||
|
|
# Constraints
|
||
|
|
solver.Add(solver.AllDifferent(letters))
|
||
|
|
|
||
|
|
# CP + IS + FUN = TRUE
|
||
|
|
term1 = solver.Sum([kBase*c, p])
|
||
|
|
term2 = solver.Sum([kBase*i, s])
|
||
|
|
term3 = solver.Sum([kBase*kBase*f, kBase*u, n])
|
||
|
|
sum_terms = solver.Sum([term1, term2, term3])
|
||
|
|
|
||
|
|
sum_value = solver.Sum([kBase*kBase*kBase*t, kBase*kBase*r, kBase*u, e])
|
||
|
|
solver.Add(sum_terms == sum_value)
|
||
|
|
|
||
|
|
all_solutions = solver.AllSolutionCollector()
|
||
|
|
# Add the interesting variables to the SolutionCollector
|
||
|
|
all_solutions.Add(letters)
|
||
|
|
|
||
|
|
db = solver.Phase(letters, solver.INT_VAR_DEFAULT,
|
||
|
|
solver.INT_VALUE_DEFAULT)
|
||
|
|
|
||
|
|
# Add some time limit
|
||
|
|
time_limit = solver.TimeLimit(gflags.FLAGS.time_limit);
|
||
|
|
|
||
|
|
solver.Solve(db, all_solutions, time_limit)
|
||
|
|
|
||
|
|
# Retrieve the solutions
|
||
|
|
numberSolutions = all_solutions.SolutionCount()
|
||
|
|
|
||
|
|
print "Number of solutions: ", numberSolutions
|
||
|
|
|
||
|
|
if (gflags.FLAGS.print_all_solutions):
|
||
|
|
for index in range(numberSolutions):
|
||
|
|
print "C=", all_solutions.Value(index, c), " P=", all_solutions.Value(index, p), " I=", \
|
||
|
|
all_solutions.Value(index, i), " S=", all_solutions.Value(index, s), " F=", all_solutions.Value(index, f), \
|
||
|
|
" U=", all_solutions.Value(index, u), " N=", all_solutions.Value(index, n), " T=", all_solutions.Value(index, t), \
|
||
|
|
" R=", all_solutions.Value(index, r), " E=", all_solutions.Value(index, e)
|
||
|
|
|
||
|
|
# Save profile in file
|
||
|
|
solver.ExportProfilingOverview("profile.txt")
|
||
|
|
|
||
|
|
return
|
||
|
|
|
||
|
|
if __name__ == '__main__':
|
||
|
|
try:
|
||
|
|
FLAGS(sys.argv) # parse flags
|
||
|
|
except gflags.FlagsError, e:
|
||
|
|
print '%s\\nUsage: %s ARGS\\n%s' % (e, sys.argv[0], FLAGS)
|
||
|
|
sys.exit(1)
|
||
|
|
CPIsFun()
|