66 lines
2.1 KiB
Python
Executable File
66 lines
2.1 KiB
Python
Executable File
#!/usr/bin/env python3
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# Copyright 2010-2021 Google LLC
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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# [START program]
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"""Solve assignment problem using linear assignment solver."""
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# [START import]
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from ortools.graph.python import linear_sum_assignment
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# [END import]
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def main():
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"""Linear Sum Assignment example."""
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# [START solver]
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assignment = linear_sum_assignment.SimpleLinearSumAssignment()
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# [END solver]
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# [START data]
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costs = [
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[90, 76, 75, 70],
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[35, 85, 55, 65],
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[125, 95, 90, 105],
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[45, 110, 95, 115],
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]
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num_workers = len(costs)
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num_tasks = len(costs[0])
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# [END data]
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# [START constraints]
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for worker in range(num_workers):
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for task in range(num_tasks):
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if costs[worker][task]:
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assignment.add_arc_with_cost(worker, task, costs[worker][task])
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# [END constraints]
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# [START solve]
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status = assignment.solve()
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# [END solve]
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# [START print_solution]
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if status == assignment.OPTIMAL:
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print(f'Total cost = {assignment.optimal_cost()}\n')
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for i in range(0, assignment.num_nodes()):
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print(f'Worker {i} assigned to task {assignment.right_mate(i)}.' +
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f' Cost = {assignment.assignment_cost(i)}')
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elif status == assignment.INFEASIBLE:
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print('No assignment is possible.')
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elif status == assignment.POSSIBLE_OVERFLOW:
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print(
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'Some input costs are too large and may cause an integer overflow.')
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# [END print_solution]
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if __name__ == '__main__':
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main()
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# [END Program]
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