new_contents: #!/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.
  # [START program]
  """Solve assignment problem for given group of workers."""
  # [START import]
  from ortools.sat.python import cp_model
  # [END import]
  
  
  def main():
      # Data
      # [START data]
      costs = [
          [90, 76, 75, 70, 50, 74],
          [35, 85, 55, 65, 48, 101],
          [125, 95, 90, 105, 59, 120],
          [45, 110, 95, 115, 104, 83],
          [60, 105, 80, 75, 59, 62],
          [45, 65, 110, 95, 47, 31],
          [38, 51, 107, 41, 69, 99],
          [47, 85, 57, 71, 92, 77],
          [39, 63, 97, 49, 118, 56],
          [47, 101, 71, 60, 88, 109],
          [17, 39, 103, 64, 61, 92],
          [101, 45, 83, 59, 92, 27],
      ]
      num_workers = len(costs)
      num_tasks = len(costs[0])
      # [END data]
  
      # Allowed groups of workers:
      # [START allowed_groups]
      group1 = [
          [0, 0, 1, 1],  # Workers 2, 3
          [0, 1, 0, 1],  # Workers 1, 3
          [0, 1, 1, 0],  # Workers 1, 2
          [1, 1, 0, 0],  # Workers 0, 1
          [1, 0, 1, 0],  # Workers 0, 2
      ]
  
      group2 = [
          [0, 0, 1, 1],  # Workers 6, 7
          [0, 1, 0, 1],  # Workers 5, 7
          [0, 1, 1, 0],  # Workers 5, 6
          [1, 1, 0, 0],  # Workers 4, 5
          [1, 0, 0, 1],  # Workers 4, 7
      ]
  
      group3 = [
          [0, 0, 1, 1],  # Workers 10, 11
          [0, 1, 0, 1],  # Workers 9, 11
          [0, 1, 1, 0],  # Workers 9, 10
          [1, 0, 1, 0],  # Workers 8, 10
          [1, 0, 0, 1],  # Workers 8, 11
      ]
      # [END allowed_groups]
  
      # Model
      # [START model]
      model = cp_model.CpModel()
      # [END model]
  
      # Variables
      # [START variables]
      x = {}
      for worker in range(num_workers):
          for task in range(num_tasks):
              x[worker, task] = model.NewBoolVar(f'x[{worker},{task}]')
      # [END variables]
  
      # Constraints
      # [START constraints]
      # Each worker is assigned to at most one task.
      for worker in range(num_workers):
          model.Add(sum(x[worker, task] for task in range(num_tasks)) <= 1)
  
      # Each task is assigned to exactly one worker.
      for task in range(num_tasks):
          model.Add(sum(x[worker, task] for worker in range(num_workers)) == 1)
      # [END constraints]
  
      # [START assignments]
      # Create variables for each worker, indicating whether they work on some task.
      work = {}
      for worker in range(num_workers):
          work[worker] = model.NewBoolVar(f'work[{worker}]')
  
      for worker in range(num_workers):
          for task in range(num_tasks):
              model.Add(work[worker] == sum(
                  x[worker, task] for task in range(num_tasks)))
  
      # Define the allowed groups of worders
      model.AddAllowedAssignments([work[0], work[1], work[2], work[3]], group1)
      model.AddAllowedAssignments([work[4], work[5], work[6], work[7]], group2)
      model.AddAllowedAssignments([work[8], work[9], work[10], work[11]], group3)
      # [END assignments]
  
      # Objective
      # [START objective]
      objective_terms = []
      for worker in range(num_workers):
          for task in range(num_tasks):
              objective_terms.append(costs[worker][task] * x[worker, task])
      model.Minimize(sum(objective_terms))
      # [END objective]
  
      # Solve
      # [START solve]
      solver = cp_model.CpSolver()
      status = solver.Solve(model)
      # [END solve]
  
      # Print solution.
      # [START print_solution]
      if status == cp_model.OPTIMAL or status == cp_model.FEASIBLE:
          print(f'Total cost = {solver.ObjectiveValue()}\n')
          for worker in range(num_workers):
              for task in range(num_tasks):
                  if solver.BooleanValue(x[worker, task]):
                      print(f'Worker {worker} assigned to task {task}.' +
                            f' Cost = {costs[worker][task]}')
      else:
          print('No solution found.')
      # [END print_solution]
  
  
  if __name__ == '__main__':
      main()
  # [END program]
  
subject: Add assignment_groups_sat.py