Create an function/algorithm in C#

I need a algorithm or function in C# that plans and creates tasks with the least number of trucks based on these rules: 1. Each truck can take either a container of size 40 or two containers 20. 2. A task or a job is about a truck drop of one or more containers (based on capacity rule 1 ) and pickup one or more containers The following are the classes. public class TaskInfo { public TruckInfo Truck { get; set; } public List<ContainerInfo> Pickup { get; set; } public List<ContainerInfo> DropOff { get; set; } } public class TruckInfo { public var PlateNo { get; set; } } public class ContainerInfo { public string ContainerNo { get; set; } public string ContainerSize { get; set; } } Using this below test data, I need winner to create a function (createtasks) that takes a list of containers to drop-off and pickup and then comes up with the best plan (by creating tasks hence ) which allows the use of the least number of trucks. List<ContainerInfo> PickupContainers = new List<ContainerInfo>(); List<ContainerInfo> dropoffcontainers = new List<ContainerInfo>(); ContainerInfo pc1 = new ContainerInfo(); [login to view URL] = "BMOU4364018"; [login to view URL] = "20"; ContainerInfo pc2 = new ContainerInfo(); [login to view URL] = "PCIU8986471"; [login to view URL] = "20"; ContainerInfo pc3 = new ContainerInfo(); [login to view URL] = "PCIU1905035"; [login to view URL] = "20"; ContainerInfo pc4 = new ContainerInfo(); [login to view URL] = "PCIU1905035"; [login to view URL] = "40"; [login to view URL](pc1); [login to view URL](pc2); [login to view URL](pc3); [login to view URL](pc4); ContainerInfo drop_con1 = new ContainerInfo(); [login to view URL] = "MTY0000240"; [login to view URL] = "20"; ContainerInfo drop_con2 = new ContainerInfo(); [login to view URL] = "MTY0000241"; [login to view URL] = "40"; ContainerInfo drop_con3 = new ContainerInfo(); [login to view URL] = "MTY0000242"; [login to view URL] = "40"; [login to view URL](drop_con1); [login to view URL](drop_con2); [login to view URL](drop_con3); List<TaskInfo> tasks = new List<TaskInfo>(); createtasks(PickupContainers, dropoffcontainers, tasks);