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ortools-clone/ortools/sat/samples/solution_hinting_sample_sat.py
Corentin Le Molgat a66a6daac7 Bump Copyright to 2025
2025-01-10 11:35:44 +01:00

62 lines
1.8 KiB
Python

#!/usr/bin/env python3
# Copyright 2010-2025 Google LLC
# 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.
"""Code sample that solves a model using solution hinting."""
# [START program]
from ortools.sat.python import cp_model
def solution_hinting_sample_sat():
"""Showcases solution hinting."""
# Creates the model.
# [START model]
model = cp_model.CpModel()
# [END model]
# Creates the variables.
# [START variables]
num_vals = 3
x = model.new_int_var(0, num_vals - 1, "x")
y = model.new_int_var(0, num_vals - 1, "y")
z = model.new_int_var(0, num_vals - 1, "z")
# [END variables]
# Creates the constraints.
# [START constraints]
model.add(x != y)
# [END constraints]
# [START objective]
model.maximize(x + 2 * y + 3 * z)
# [END objective]
# Solution hinting: x <- 1, y <- 2
model.add_hint(x, 1)
model.add_hint(y, 2)
# Creates a solver and solves.
# [START solve]
solver = cp_model.CpSolver()
solution_printer = cp_model.VarArrayAndObjectiveSolutionPrinter([x, y, z])
status = solver.solve(model, solution_printer)
# [END solve]
print(f"Status = {solver.status_name(status)}")
print(f"Number of solutions found: {solution_printer.solution_count}")
solution_hinting_sample_sat()
# [END program]