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ortools-clone/ortools/sat/samples/optional_interval_sample_sat.py
2021-10-18 16:17:46 +02:00

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#!/usr/bin/env python3
# Copyright 2010-2021 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 to demonstrates how to build an optional interval."""
from ortools.sat.python import cp_model
def OptionalIntervalSampleSat():
"""Showcases how to build optional interval variables."""
model = cp_model.CpModel()
horizon = 100
# An interval can be created from three affine expressions.
start_var = model.NewIntVar(0, horizon, 'start')
duration = 10 # Python cp/sat code accept integer variables or constants.
end_var = model.NewIntVar(0, horizon, 'end')
presence_var = model.NewBoolVar('presence')
interval_var = model.NewOptionalIntervalVar(start_var, duration,
end_var + 2, presence_var,
'interval')
print(f'interval = {repr(interval_var)}')
# If the size is fixed, a simpler version uses the start expression and the
# size.
fixed_size_interval_var = model.NewOptionalFixedSizeIntervalVar(
start_var, 10, presence_var, 'fixed_size_interval_var')
print(f'fixed_size_interval_var = {repr(fixed_size_interval_var)}')
# A fixed interval can be created using the same API.
fixed_interval = model.NewOptionalFixedSizeIntervalVar(
5, 10, presence_var, 'fixed_interval')
print(f'fixed_interval = {repr(fixed_interval)}')
OptionalIntervalSampleSat()