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ortools-clone/examples/notebook/sat/assignment_groups_sat.ipynb
Corentin Le Molgat 949ff20da4 Update notebooks...
2021-12-06 10:19:50 +01:00

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{
"cells": [
{
"cell_type": "markdown",
"id": "be201470",
"metadata": {},
"source": [
"##### Copyright 2021 Google LLC."
]
},
{
"cell_type": "markdown",
"id": "e3803804",
"metadata": {},
"source": [
"Licensed under the Apache License, Version 2.0 (the \"License\");\n",
"you may not use this file except in compliance with the License.\n",
"You may obtain a copy of the License at\n",
"\n",
" http://www.apache.org/licenses/LICENSE-2.0\n",
"\n",
"Unless required by applicable law or agreed to in writing, software\n",
"distributed under the License is distributed on an \"AS IS\" BASIS,\n",
"WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n",
"See the License for the specific language governing permissions and\n",
"limitations under the License.\n"
]
},
{
"cell_type": "markdown",
"id": "c54bc54c",
"metadata": {},
"source": [
"# assignment_groups_sat"
]
},
{
"cell_type": "markdown",
"id": "fd3f9a16",
"metadata": {},
"source": [
"<table align=\"left\">\n",
"<td>\n",
"<a href=\"https://colab.research.google.com/github/google/or-tools/blob/master/examples/notebook/sat/assignment_groups_sat.ipynb\"><img src=\"https://raw.githubusercontent.com/google/or-tools/master/tools/colab_32px.png\"/>Run in Google Colab</a>\n",
"</td>\n",
"<td>\n",
"<a href=\"https://github.com/google/or-tools/blob/master/ortools/sat/samples/assignment_groups_sat.py\"><img src=\"https://raw.githubusercontent.com/google/or-tools/master/tools/github_32px.png\"/>View source on GitHub</a>\n",
"</td>\n",
"</table>"
]
},
{
"cell_type": "markdown",
"id": "5c2119e2",
"metadata": {},
"source": [
"First, you must install [ortools](https://pypi.org/project/ortools/) package in this colab."
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ca65dd32",
"metadata": {},
"outputs": [],
"source": [
"!pip install ortools"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "b6bc35ee",
"metadata": {},
"outputs": [],
"source": [
"#!/usr/bin/env python3\n",
"# Copyright 2010-2021 Google LLC\n",
"# Licensed under the Apache License, Version 2.0 (the \"License\");\n",
"# you may not use this file except in compliance with the License.\n",
"# You may obtain a copy of the License at\n",
"#\n",
"# http://www.apache.org/licenses/LICENSE-2.0\n",
"#\n",
"# Unless required by applicable law or agreed to in writing, software\n",
"# distributed under the License is distributed on an \"AS IS\" BASIS,\n",
"# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n",
"# See the License for the specific language governing permissions and\n",
"# limitations under the License.\n",
"# [START program]\n",
"\"\"\"Solve assignment problem for given group of workers.\"\"\"\n",
"# [START import]\n",
"from ortools.sat.python import cp_model\n",
"# [END import]\n",
"\n",
"\n",
"# Data\n",
"# [START data]\n",
"costs = [\n",
" [90, 76, 75, 70, 50, 74],\n",
" [35, 85, 55, 65, 48, 101],\n",
" [125, 95, 90, 105, 59, 120],\n",
" [45, 110, 95, 115, 104, 83],\n",
" [60, 105, 80, 75, 59, 62],\n",
" [45, 65, 110, 95, 47, 31],\n",
" [38, 51, 107, 41, 69, 99],\n",
" [47, 85, 57, 71, 92, 77],\n",
" [39, 63, 97, 49, 118, 56],\n",
" [47, 101, 71, 60, 88, 109],\n",
" [17, 39, 103, 64, 61, 92],\n",
" [101, 45, 83, 59, 92, 27],\n",
"]\n",
"num_workers = len(costs)\n",
"num_tasks = len(costs[0])\n",
"# [END data]\n",
"\n",
"# Allowed groups of workers:\n",
"# [START allowed_groups]\n",
"group1 = [\n",
" [0, 0, 1, 1], # Workers 2, 3\n",
" [0, 1, 0, 1], # Workers 1, 3\n",
" [0, 1, 1, 0], # Workers 1, 2\n",
" [1, 1, 0, 0], # Workers 0, 1\n",
" [1, 0, 1, 0], # Workers 0, 2\n",
"]\n",
"\n",
"group2 = [\n",
" [0, 0, 1, 1], # Workers 6, 7\n",
" [0, 1, 0, 1], # Workers 5, 7\n",
" [0, 1, 1, 0], # Workers 5, 6\n",
" [1, 1, 0, 0], # Workers 4, 5\n",
" [1, 0, 0, 1], # Workers 4, 7\n",
"]\n",
"\n",
"group3 = [\n",
" [0, 0, 1, 1], # Workers 10, 11\n",
" [0, 1, 0, 1], # Workers 9, 11\n",
" [0, 1, 1, 0], # Workers 9, 10\n",
" [1, 0, 1, 0], # Workers 8, 10\n",
" [1, 0, 0, 1], # Workers 8, 11\n",
"]\n",
"# [END allowed_groups]\n",
"\n",
"# Model\n",
"# [START model]\n",
"model = cp_model.CpModel()\n",
"# [END model]\n",
"\n",
"# Variables\n",
"# [START variables]\n",
"x = {}\n",
"for worker in range(num_workers):\n",
" for task in range(num_tasks):\n",
" x[worker, task] = model.NewBoolVar(f'x[{worker},{task}]')\n",
"# [END variables]\n",
"\n",
"# Constraints\n",
"# [START constraints]\n",
"# Each worker is assigned to at most one task.\n",
"for worker in range(num_workers):\n",
" model.Add(sum(x[worker, task] for task in range(num_tasks)) <= 1)\n",
"\n",
"# Each task is assigned to exactly one worker.\n",
"for task in range(num_tasks):\n",
" model.Add(sum(x[worker, task] for worker in range(num_workers)) == 1)\n",
"# [END constraints]\n",
"\n",
"# [START assignments]\n",
"# Create variables for each worker, indicating whether they work on some task.\n",
"work = {}\n",
"for worker in range(num_workers):\n",
" work[worker] = model.NewBoolVar(f'work[{worker}]')\n",
"\n",
"for worker in range(num_workers):\n",
" for task in range(num_tasks):\n",
" model.Add(work[worker] == sum(\n",
" x[worker, task] for task in range(num_tasks)))\n",
"\n",
"# Define the allowed groups of worders\n",
"model.AddAllowedAssignments([work[0], work[1], work[2], work[3]], group1)\n",
"model.AddAllowedAssignments([work[4], work[5], work[6], work[7]], group2)\n",
"model.AddAllowedAssignments([work[8], work[9], work[10], work[11]], group3)\n",
"# [END assignments]\n",
"\n",
"# Objective\n",
"# [START objective]\n",
"objective_terms = []\n",
"for worker in range(num_workers):\n",
" for task in range(num_tasks):\n",
" objective_terms.append(costs[worker][task] * x[worker, task])\n",
"model.Minimize(sum(objective_terms))\n",
"# [END objective]\n",
"\n",
"# Solve\n",
"# [START solve]\n",
"solver = cp_model.CpSolver()\n",
"status = solver.Solve(model)\n",
"# [END solve]\n",
"\n",
"# Print solution.\n",
"# [START print_solution]\n",
"if status == cp_model.OPTIMAL or status == cp_model.FEASIBLE:\n",
" print(f'Total cost = {solver.ObjectiveValue()}\\n')\n",
" for worker in range(num_workers):\n",
" for task in range(num_tasks):\n",
" if solver.BooleanValue(x[worker, task]):\n",
" print(f'Worker {worker} assigned to task {task}.' +\n",
" f' Cost = {costs[worker][task]}')\n",
"else:\n",
" print('No solution found.')\n",
"# [END print_solution]\n",
"\n"
]
}
],
"metadata": {},
"nbformat": 4,
"nbformat_minor": 5
}