95 lines
3.5 KiB
Plaintext
95 lines
3.5 KiB
Plaintext
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{
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"cells": [
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{
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"cell_type": "code",
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"execution_count": null,
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"metadata": {},
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"outputs": [],
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"source": [
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"# Copyright 2010-2018 Google LLC\n",
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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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"\"\"\"Small example to illustrate solving a MIP problem.\"\"\"\n",
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"# [START program]\n",
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"from __future__ import print_function\n",
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"# [START import]\n",
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"from ortools.linear_solver import pywraplp\n",
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"# [END import]\n",
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"\n",
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"\n",
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"def IntegerProgrammingExample():\n",
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" \"\"\"Integer programming sample.\"\"\"\n",
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" # [START solver]\n",
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" # Create the mip solver with the CBC backend.\n",
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" solver = pywraplp.Solver('IntegerProgrammingExample',\n",
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" pywraplp.Solver.CBC_MIXED_INTEGER_PROGRAMMING)\n",
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" # [END solver]\n",
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"\n",
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" # [START variables]\n",
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" # x, y, and z are non-negative integer variables.\n",
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" x = solver.IntVar(0.0, solver.infinity(), 'x')\n",
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" y = solver.IntVar(0.0, solver.infinity(), 'y')\n",
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" z = solver.IntVar(0.0, solver.infinity(), 'z')\n",
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" # [END variables]\n",
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"\n",
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" # [START constraints]\n",
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" # 2*x + 7*y + 3*z <= 50\n",
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" constraint0 = solver.Constraint(-solver.infinity(), 50)\n",
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" constraint0.SetCoefficient(x, 2)\n",
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" constraint0.SetCoefficient(y, 7)\n",
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" constraint0.SetCoefficient(z, 3)\n",
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"\n",
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" # 3*x - 5*y + 7*z <= 45\n",
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" constraint1 = solver.Constraint(-solver.infinity(), 45)\n",
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" constraint1.SetCoefficient(x, 3)\n",
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" constraint1.SetCoefficient(y, -5)\n",
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" constraint1.SetCoefficient(z, 7)\n",
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"\n",
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" # 5*x + 2*y - 6*z <= 37\n",
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" constraint2 = solver.Constraint(-solver.infinity(), 37)\n",
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" constraint2.SetCoefficient(x, 5)\n",
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" constraint2.SetCoefficient(y, 2)\n",
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" constraint2.SetCoefficient(z, -6)\n",
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" # [END constraints]\n",
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"\n",
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" # [START objective]\n",
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" # Maximize 2*x + 2*y + 3*z\n",
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" objective = solver.Objective()\n",
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" objective.SetCoefficient(x, 2)\n",
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" objective.SetCoefficient(y, 2)\n",
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" objective.SetCoefficient(z, 3)\n",
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" objective.SetMaximization()\n",
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" # [END objective]\n",
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"\n",
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" # Solve the problem and print the solution.\n",
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" # [START print_solution]\n",
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" solver.Solve()\n",
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" # Print the objective value of the solution.\n",
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" print('Maximum objective function value = %d' % solver.Objective().Value())\n",
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" print()\n",
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" # Print the value of each variable in the solution.\n",
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" for variable in [x, y, z]:\n",
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" print('%s = %d' % (variable.name(), variable.solution_value()))\n",
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" # [END print_solution]\n",
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"\n",
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"\n",
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"IntegerProgrammingExample()\n",
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"# [END program]\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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"nbformat": 4,
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"nbformat_minor": 4
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}
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