Files
ortools-clone/examples/contrib/organize_day.cs
2020-11-03 10:15:53 +01:00

131 lines
3.5 KiB
C#

//
// Copyright 2012 Hakan Kjellerstrand
//
// 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.
using System;
using System.Collections;
using System.IO;
using System.Linq;
using System.Text.RegularExpressions;
using Google.OrTools.ConstraintSolver;
public class OrganizeDay
{
//
// No overlapping of tasks s1 and s2
//
public static void NoOverlap(Solver solver, IntVar s1, int d1, IntVar s2, int d2)
{
solver.Add((s1 + d1 <= s2) + (s2 + d2 <= s1) == 1);
}
/**
*
*
* Organizing a day.
*
* Simple scheduling problem.
*
* Problem formulation from ECLiPSe:
* Slides on (Finite Domain) Constraint Logic Programming, page 38f
* http://eclipseclp.org/reports/eclipse.ppt
*
*
* Also see http://www.hakank.org/google_or_tools/organize_day.py
*
*/
private static void Solve()
{
Solver solver = new Solver("OrganizeDay");
int n = 4;
int work = 0;
int mail = 1;
int shop = 2;
int bank = 3;
int[] tasks = { work, mail, shop, bank };
int[] durations = { 4, 1, 2, 1 };
// task [i,0] must be finished before task [i,1]
int[,] before_tasks = { { bank, shop }, { mail, work } };
// the valid times of the day
int begin = 9;
int end = 17;
//
// Decision variables
//
IntVar[] begins = solver.MakeIntVarArray(n, begin, end, "begins");
IntVar[] ends = solver.MakeIntVarArray(n, begin, end, "ends");
//
// Constraints
//
foreach (int t in tasks)
{
solver.Add(ends[t] == begins[t] + durations[t]);
}
foreach (int i in tasks)
{
foreach (int j in tasks)
{
if (i < j)
{
NoOverlap(solver, begins[i], durations[i], begins[j], durations[j]);
}
}
}
// specific constraints
for (int t = 0; t < before_tasks.GetLength(0); t++)
{
solver.Add(ends[before_tasks[t, 0]] <= begins[before_tasks[t, 1]]);
}
solver.Add(begins[work] >= 11);
//
// Search
//
DecisionBuilder db = solver.MakePhase(begins, Solver.INT_VAR_DEFAULT, Solver.INT_VALUE_DEFAULT);
solver.NewSearch(db);
while (solver.NextSolution())
{
foreach (int t in tasks)
{
Console.WriteLine("Task {0}: {1,2} .. ({2}) .. {3,2}", t, begins[t].Value(), durations[t],
ends[t].Value());
}
Console.WriteLine();
}
Console.WriteLine("\nSolutions: {0}", solver.Solutions());
Console.WriteLine("WallTime: {0}ms", solver.WallTime());
Console.WriteLine("Failures: {0}", solver.Failures());
Console.WriteLine("Branches: {0} ", solver.Branches());
solver.EndSearch();
}
public static void Main(String[] args)
{
Solve();
}
}