87 lines
2.9 KiB
Plaintext
87 lines
2.9 KiB
Plaintext
{
|
|
"cells": [
|
|
{
|
|
"cell_type": "code",
|
|
"execution_count": null,
|
|
"metadata": {},
|
|
"outputs": [],
|
|
"source": [
|
|
"# Copyright 2010-2018 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",
|
|
"\"\"\"Integer programming examples that show how to use the APIs.\"\"\"\n",
|
|
"# [START program]\n",
|
|
"# [START import]\n",
|
|
"from __future__ import print_function\n",
|
|
"from ortools.linear_solver import pywraplp\n",
|
|
"# [END import]\n",
|
|
"\n",
|
|
"\n",
|
|
"# [START solver]\n",
|
|
"# Create the mip solver with the CBC backend.\n",
|
|
"solver = pywraplp.Solver('simple_mip_program',\n",
|
|
" pywraplp.Solver.CBC_MIXED_INTEGER_PROGRAMMING)\n",
|
|
"# [END solver]\n",
|
|
"\n",
|
|
"# [START variables]\n",
|
|
"infinity = solver.infinity()\n",
|
|
"# x and y are integer non-negative variables.\n",
|
|
"x = solver.IntVar(0.0, infinity, 'x')\n",
|
|
"y = solver.IntVar(0.0, infinity, 'y')\n",
|
|
"\n",
|
|
"print('Number of variables =', solver.NumVariables())\n",
|
|
"# [END variables]\n",
|
|
"\n",
|
|
"# [START constraints]\n",
|
|
"# x + 7 * y <= 17.5.\n",
|
|
"solver.Add(x + 7 * y <= 17.5)\n",
|
|
"\n",
|
|
"# x <= 3.5.\n",
|
|
"solver.Add(x <= 3.5)\n",
|
|
"\n",
|
|
"print('Number of constraints =', solver.NumConstraints())\n",
|
|
"# [END constraints]\n",
|
|
"\n",
|
|
"# [START objective]\n",
|
|
"# Maximize x + 10 * y.\n",
|
|
"solver.Maximize(x + 10 * y)\n",
|
|
"# [END objective]\n",
|
|
"\n",
|
|
"# [START solve]\n",
|
|
"status = solver.Solve()\n",
|
|
"# [END solve]\n",
|
|
"\n",
|
|
"# [START print_solution]\n",
|
|
"if status == pywraplp.Solver.OPTIMAL:\n",
|
|
" print('Solution:')\n",
|
|
" print('Objective value =', solver.Objective().Value())\n",
|
|
" print('x =', x.solution_value())\n",
|
|
" print('y =', y.solution_value())\n",
|
|
"else:\n",
|
|
" print('The problem does not have an optimal solution.')\n",
|
|
"# [END print_solution]\n",
|
|
"\n",
|
|
"# [START advanced]\n",
|
|
"print('\\nAdvanced usage:')\n",
|
|
"print('Problem solved in %f milliseconds' % solver.wall_time())\n",
|
|
"print('Problem solved in %d iterations' % solver.iterations())\n",
|
|
"print('Problem solved in %d branch-and-bound nodes' % solver.nodes())\n",
|
|
"# [END advanced]\n",
|
|
"\n"
|
|
]
|
|
}
|
|
],
|
|
"metadata": {},
|
|
"nbformat": 4,
|
|
"nbformat_minor": 4
|
|
}
|