Question

Write a program that inserts 25 random integers from 0 to 100 in order into a linked-list object. The program should calculate the sum of the elements and the floating- point average of the elements.

Short answer

Create a linked-list, insert random integers, compute their sum and average.

Step-by-step solution

Initialize Linked-List

Create a linked-list class that can hold integer values. The linked-list will have nodes with two attributes: a value (the integer) and a pointer to the next node.

Generating Random Integers

Use a random number generator to produce 25 random integers between 0 and 100. Ensure the random function generates numbers inclusively within this range.

Inserting Integers into Linked-List

Iterate through each generated random integer and insert it into the linked-list in such a way that the linked-list maintains the order of insertion. This means appending each new value to the end of the list.

Calculate the Sum of Elements

Traverse through the linked-list starting from the head node, and add up all the integer values stored in each node. Keep a running total to compute the sum.

Compute the Floating-Point Average

Use the sum calculated in the previous step to compute the average. Divide the sum by the number of elements (25 in this case) to get the floating-point average.

Key concepts

random integers

In the context of our Java program, random integers are numbers selected from a specified range, generated unpredictably by a computer. Producing random integers in Java can be achieved using the `Random` class from the `java.util` package. First, create an instance of this class, and use the `nextInt(upperBound)` method to generate numbers. For instance, `nextInt(101)` creates integers between 0 and 100, inclusive. This is crucial for injecting variability into your linked list program, allowing different execution results each time you run the code.
This variability is useful for testing and validating algorithms under different input conditions. It also simulates natural randomness, which can be applied in multiple domains like simulations or games.

calculate sum

Calculating the sum of integers in a linked list involves iterating through each node and accumulating their values. In Java, starting from the head of the linked list, you move to the next node until you reach the end (where the next node is null). For each node, access its value using a method such as `getValue()` or directly retrieve the value property, and add it to a total sum variable initialized to zero.
This process is straightforward but requires understanding how to traverse a linked list, a fundamental skill in managing data structures in programming. Ensure the traversal correctly sums up all elements to prevent logic errors, especially when the list grows larger.

floating-point average

The floating-point average provides more precision than a simple integer division average since it includes decimal places. To calculate this, first ensure you have the sum of all integers from the linked list and the count of these numbers, which is 25 in the earlier example. Then, divide the total sum by the count, using a floating-point division to ensure the decimal part of the result is not lost.
In Java, this can be achieved by either casting the sum or count to a `double` before dividing. For example, `(double) sum / count` guarantees that the division retains decimal precision, crucial for applications requiring detailed metrics or data analyses.

programming in Java

Java is a widely-used object-oriented language known for its portability and efficiency in handling complex data structures, like linked lists. Its syntax bears resemblance to both C++ and C#, making it accessible yet powerful.

• **Object-Oriented:** Supports encapsulation, inheritance, and polymorphism, essential for code reuse and modularity.
• **Robust:** Offers garbage collection to manage memory, reducing manual error handling for memory leaks.
• **Portable:** Once compiled, Java programs can run on any device with a Java Virtual Machine (JVM).

In practice, programming in Java means embracing its strengths in both developing backend applications and tackling data-intensive tasks like managing a linked list. Understanding Java's built-in libraries also processes random number generation, enabling programmers to create applications such as the one described in the problem statement efficiently.