Train Information Program Using Structure in C

In C programming language, structure is a user defined data type. It is useful when you want to store several data items of different kinds together.

In this program, the system takes details of passengers and stores them in a structure. Using this, the user can search for the desired train.

Creating a Structure

A C structure is a custom data type in the C programming language that allows you to group multiple data types into a single unit. Each of the data elements within a structure is called a member or field.

A structure is similar to a record in other languages. It specifies a sequence of variable values (called members or fields) with different types, and an optional identifier name (called a tag) to use in references to the structure.

During program development, a structured data type can be used for a variety of tasks such as storing records in a database, displaying a list of contacts, or storing a directory entry. The syntax for defining a structure is the same as for other C primitive data types.

To define a structure, the struct keyword is used, followed by a name of the structure and data_type variable1; for member variables. The name of the structure can be short or new, while the data_type variable1; declaration statement specifies the type of the member variable.

After a structure is defined, it must be initialized before it can be used in the program. The struct declaration doesn’t set aside memory for the structure, but it does create a pointer to the structure that can be accessed by any other function.

There are three ways to initialize a structure: using the dot operator, curly braces, or designated initialization. In designated initialization, a structure’s members are initialized in any order.

If a structure’s members are not initialized, then all of them are null or 0 for value type members and string type data. When you access a member of the structure, you must first specify the name of the structure and the member name with the dot operator or the curly braces.

Another way to initialize a structure is to assign a value to a specific number of members. Alternatively, you can initialize all of the members with zero or the structure’s default value.

When a struct’s members are not initialized, they can’t be manipulated by other functions except by assignment. However, when a structure’s members are initialized, they can be passed as arguments to other functions or returned from them.

Creating a Linked List

Linked lists are one of the most commonly used data structures. They are linearly connected in memory and allow for constant time complexity when it comes to insertion or deletion of elements at any position.

They are a very simple data structure that can be used for many applications, including graphs (plotting distances between cities on a map), trees (hierarchies in an organization), and other similar applications. They are often implemented in conjunction with Array Lists for storage and access, but can also be implemented as standalone data structures.

In a linked list, each node contains data and a pointer to the next node. Each node is a separate block of memory, and each data point in the list can be accessed sequentially.

To visualize this concept, think about a train that has coaches connected by connectors. Each coach is a node in the linked list and each connection between the coaches is a data point.

The first node is the engine, and each connector in the train connects two coaches. If a node is removed, it is deleted from the linked list.

A train also has a last coach, but it is not further connected to any of the coaches. This makes it easier to detach a single car from the train than removing several cars in different locations.

Similarly, in a linked list the last node is easier to remove than removing several nodes in the middle. Once a node has been removed, its next pointer can be changed to null or a dummy node to avoid accidentally pointing to a random location in memory.

Another advantage of a linked list is that it does not require a lot of memory. Since it can be inserted and removed in a very linear fashion, there is no need to allocate lots of memory for each element.

This is very important to keep in mind when using a linked list, because it can be quite annoying to have an array that is too large. Fortunately, a linked list can be modified to be smaller, which can make it much easier to work with.

Creating a Passenger

During disruptions, passengers are affected by changes to the train schedule and station closures. The information provided to them must be accurate and available, and must be delivered quickly. This requires data collection and dissemination, which is time-consuming and resource-intensive.

Passenger information can be published in different forms: disruption updates at stations (web or GTFS), notifications via SMS, email, or app; or real-time passenger information that uses GPS tracking to publish delays and other changes to a vehicle’s position. While these technologies are effective, they have a number of limitations: They may not always be available, they can be inaccurate or unreliable, and they can be difficult to co-ordinate between different organisations.

To address these issues, a dynamic passenger assignment framework is introduced, which takes time-dependent demand, service variations and vehicle capacity constraints into account. It also enables passengers to re-plan their paths as soon as they receive information about their service variations.

Part I implements the original timetable as an event-activity network Gplan, in which each arrival and departure event is described by attributes corresponding to the passenger’s origin, destination and arrival times at the respective station. The planned path of a passenger is determined by performing a shortest path algorithm on the network.

As a result of the algorithm, passengers are assigned to their preferred planned paths, which are updated when they receive information about their service variations. These re-planned paths are then formulated as a directed acyclic graph (DAG) with passenger perceived times on arcs, assuming that passengers are rational agents.

Several parts are implemented in this framework, including loading and unloading procedures, which are implemented using discrete event simulation. Moreover, passenger re-planning actions are realized by searching their re-planned paths with the shortest possible time.

In addition, a network formulation is introduced, which includes an adaptive event-activity network in which some run activities are excluded due to reaching a specific level ratio of train congestions as notified to passengers (lines 15-17). This ensures that the re-plan of some passengers will be limited to those trains that are highly congested as notified and excludes those that are not.

Creating a Result

A result is the output of a program. This is a collection of information that can be displayed to users or stored in the computer memory. For example, this might include a count of passengers waiting on a particular train or a list of scheduled service changes and station closures.

Creating a result requires a bit of code that combines several pieces of functionality together to create the output you want. For example, you may need to use a structure (also known as a struct) to group different variables into one place.

Structures are also used for storage of data. They contain a range of data members, including strings, integers, floats, and other data types. They are often used in conjunction with arrays to store more complex data.

To access a structure, you can either create a variable of the same name and assign it to the member you want to read or you can write to the member. You can also use the dot syntax to assign values to members in a single line of code.

You can also manipulate a structure with functions like insert_passenger_after, which inserts a new passenger into a linked list directly after the first node. Similarly, you can calculate the average waiting time of all the passengers in a linked list with a function called double average_passenger_list.

These functions can be found in the libc library, which is an implementation of the C standard that includes many useful features for programmers. They are used to make it easier to write and test programs.

The functions mentioned above are just a small sample of the functionality available in the libc library. Other features you can find include functions that help you handle exceptions, write to files, and perform operations on arrays.

Using the libc library, you can create a simple program that counts the number of passengers on a train. To do this, you need to implement a function that accepts a count of passengers and a count of trains.