128 lines
3.5 KiB
Plaintext
128 lines
3.5 KiB
Plaintext
{
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"cells": [
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{
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"cell_type": "markdown",
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"id": "google",
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"metadata": {},
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"source": [
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"##### Copyright 2025 Google LLC."
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]
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},
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{
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"cell_type": "markdown",
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"id": "apache",
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"metadata": {},
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"source": [
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"Licensed under the Apache License, Version 2.0 (the \"License\");\n",
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"you may not use this file except in compliance with the License.\n",
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"You may obtain a copy of the License at\n",
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"\n",
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" http://www.apache.org/licenses/LICENSE-2.0\n",
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"\n",
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"Unless required by applicable law or agreed to in writing, software\n",
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"distributed under the License is distributed on an \"AS IS\" BASIS,\n",
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"WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n",
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"See the License for the specific language governing permissions and\n",
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"limitations under the License.\n"
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]
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},
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{
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"cell_type": "markdown",
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"id": "basename",
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"metadata": {},
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"source": [
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"# set_cover"
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]
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},
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{
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"cell_type": "markdown",
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"id": "link",
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"metadata": {},
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"source": [
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"<table align=\"left\">\n",
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"<td>\n",
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"<a href=\"https://colab.research.google.com/github/google/or-tools/blob/main/examples/notebook/set_cover/set_cover.ipynb\"><img src=\"https://raw.githubusercontent.com/google/or-tools/main/tools/colab_32px.png\"/>Run in Google Colab</a>\n",
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"</td>\n",
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"<td>\n",
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"<a href=\"https://github.com/google/or-tools/blob/main/ortools/set_cover/samples/set_cover.py\"><img src=\"https://raw.githubusercontent.com/google/or-tools/main/tools/github_32px.png\"/>View source on GitHub</a>\n",
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"</td>\n",
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"</table>"
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]
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},
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{
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"cell_type": "markdown",
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"id": "doc",
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"metadata": {},
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"source": [
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"First, you must install [ortools](https://pypi.org/project/ortools/) package in this colab."
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"id": "install",
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"metadata": {},
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"outputs": [],
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"source": [
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"%pip install ortools"
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]
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},
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{
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"cell_type": "markdown",
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"id": "description",
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"metadata": {},
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"source": [
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"\n",
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"A simple set-covering problem.\n"
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]
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},
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{
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"cell_type": "code",
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"execution_count": null,
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"id": "code",
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"metadata": {},
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"outputs": [],
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"source": [
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"from ortools.set_cover.python import set_cover\n",
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"\n",
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"\n",
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"\n",
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"def main():\n",
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" model = set_cover.SetCoverModel()\n",
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" model.add_empty_subset(2.0)\n",
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" model.add_element_to_last_subset(0)\n",
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" model.add_empty_subset(2.0)\n",
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" model.add_element_to_last_subset(1)\n",
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" model.add_empty_subset(1.0)\n",
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" model.add_element_to_last_subset(0)\n",
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" model.add_element_to_last_subset(1)\n",
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"\n",
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" inv = set_cover.SetCoverInvariant(model)\n",
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" greedy = set_cover.GreedySolutionGenerator(inv)\n",
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" has_found = greedy.next_solution()\n",
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" if not has_found:\n",
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" print(\"No solution found by the greedy heuristic.\")\n",
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" return\n",
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" solution = inv.export_solution_as_proto()\n",
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"\n",
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" print(f\"Total cost: {solution.cost}\") # == inv.cost()\n",
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" print(f\"Total number of selected subsets: {solution.num_subsets}\")\n",
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" print(\"Chosen subsets:\")\n",
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" for subset in solution.subset:\n",
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" print(f\" {subset}\")\n",
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"\n",
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"\n",
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"main()\n",
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"\n"
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]
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}
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],
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"metadata": {
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"language_info": {
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"name": "python"
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}
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},
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"nbformat": 4,
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"nbformat_minor": 5
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}
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