Question

我想使用 Microsoft Solver Framework 安排任务。现在我有一个简单的目标，就是在队列中排序任务，这样我就可以获得最短的项目时间。（后来我希望有多个队列）。我尝试通过以下设置来解决这个问题：

的决定：
- projectFinish
- 启动
- 光洁度
的参数：
- 持续时间
的约束：
- start + duration = finish
- 一次不超过一项任务
- projectFinish
的目标：
- 最小化projectFinish

到目前为止，这是我的代码

    static void Main(string[] args) {
        var data = new List<Task>() {
            new Task(){ Duration = 1, Name = "task0"},
            new Task(){ Duration = 1, Name = "task1"},
            new Task(){ Duration = 1, Name = "task2"},
        };

        SolveScheduling(data);
    }

    public class Task {
        private static int id_counter = 0;
        public Task() { ID = id_counter++; }
        public int ID { get; private set; }
        public string Name { get; set; }
        public double Duration { get; set; }
    }

    private static void SolveScheduling(IEnumerable<Task> data) {

        SolverContext context = SolverContext.GetContext();
        Model model = context.CreateModel();

        var set = new Set(Domain.Any,"TaskSet");


        var projectFinish = new Decision(Domain.IntegerNonnegative, "projectFinish");
        model.AddDecision(projectFinish);

        var taskSet = new Set(Domain.Any, "tasks");

        var durations = new Parameter(Domain.RealNonnegative, "durations", taskSet);
        durations.SetBinding(data, "Duration", "Name");
        var ids = new Parameter(Domain.Integer, "ids", taskSet);
        ids.SetBinding(data, "ID", "Name");
        var starts = new Decision(Domain.RealNonnegative, "starts", taskSet);
        var finishs = new Decision(Domain.RealNonnegative, "finishs", taskSet);

        model.AddDecisions(starts, finishs);
        model.AddParameters(durations, ids);

        // Constraints

        // start + duration = finish
        model.AddConstraint("constraint0", Model.ForEach(taskSet, (t) => starts[t] + durations[t] == finishs[t]));
        // Tasks after each other
        model.AddConstraint("constraint1", Model.ForEach(taskSet, t =>
            Model.ForEachWhere(taskSet, t2 =>  Model.Or(finishs[t] < starts[t2] , starts[t] > finishs[t2]), (t2) => ids[t] != ids[t2])));
        // projectFinish after all tasks finished
        model.AddConstraint("constraint2", Model.ForEach(taskSet, t => projectFinish >= finishs[t]));

        // Goals
        model.AddGoal("goal0", GoalKind.Minimize, projectFinish); 


        Solution solution = context.Solve();//new SimplexDirective());

        Report report = solution.GetReport();
        Console.WriteLine(@"===== report =====");
        Console.Write("{0}", report);
        Console.ReadLine();
    }

现在的问题是它需要永远解决这个问题（虽然它只有3个任务和1个队列）。我在这里缺少什么，如何提高解决速度。

更新

我找到了解决问题的方法。如果您有任何改进，请随时发表评论。这是我的代码：

        SolverContext context = SolverContext.GetContext();
        Model model = context.CreateModel();

        // === Sets ===
        var taskSet = new Set(0,data.Count(), 1);

        // === Parameters ===
        var duration = new Parameter(Domain.RealNonnegative, "durations", taskSet);
        var id = new Parameter(Domain.RealNonnegative, "id", taskSet);
        duration.SetBinding(data, "Duration", "ID");
        id.SetBinding(data, "ID", "ID");

        model.AddParameters(duration, id);

        // === Decisions ===
        var projectFinish = new Decision(Domain.RealNonnegative, "projectFinish");
        var start = new Decision(Domain.RealNonnegative, "starts", taskSet);
        var finish = new Decision(Domain.RealNonnegative, "finishs", taskSet);

        model.AddDecisions(projectFinish, start, finish);

        // === Constraints ===
        model.AddConstraint("constraint0", start[0] == 0);
        // start + duration = finish
        model.AddConstraint("constraint1", Model.ForEach(taskSet, (t) => start[t] + duration[t] == finish[t]));           
        // projectFinish after all tasks finished
        model.AddConstraint("constraint2", Model.ForEach(taskSet, t => projectFinish >= finish[t]));
        // not more than one task at a time
        model.AddConstraint("constraint3", Model.ForEach(taskSet, t =>
            Model.ForEachWhere(taskSet, t2 => Model.Or(finish[t] < start[t2], start[t] > finish[t2]), (t2) => id[t] != id[t2])));


        // === Goals ===
        model.AddGoal("goal0", GoalKind.Minimize, projectFinish); // minimieren der projekt zeit

        // === Solve ===
        context.CheckModel();
        Solution solution = context.Solve();

Answer 1

我找到了一个适合我的解决方案。我改变了taskSet

var taskSet = new Set(0, data.Count(), 1);

并添加了新约束

model.AddConstraint("constraint", starts[0] == 0);

我更新了问题

使用MS Solver Framework进行C＃调度任务

1 个答案: