我想使用Microsoft Solver Framework安排任务。现在我有一个简单的目标，就是将任务排在队列中，这样我就可以获得最少的项目时间。（后来我想要不止一个队列）。我尝试使用以下设置来解决此问题：
- 决定：
- 项目完成
- 开始
- 结束
- 范围：
- 期间
- 约束：
- 开始+持续时间=结束
- 一次不超过一项任务
- projectFinish 在所有任务完成后
- 目标：
- 最小化项目完成
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（尽管它只有 3 个任务和 1 个队列）。我在这里缺少什么以及如何提高解决速度。
更新
我找到了解决我的问题的方法。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();