Question

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

Short answer

The program initializes a linked list, inserts 25 random integers into it, calculates their sum, and computes the average as the sum divided by the count of elements (25).

Step-by-step solution

Import Necessary Modules

Import the modules needed for the program. In this case, import the 'random' module to generate random integers and import 'collections' module to use the 'deque' class (or define a node-based linked list class if a custom implementation is intended).

Initialize the Linked List

Create an instance of a linked list. If using 'deque', simply instantiate it. For a custom linked list, define a class for the linked list with methods for insertion and traversal.

Insert Random Integers

Use a loop to insert 25 random integers between 0 and 100 into the linked list. Use the 'random.randint(0, 100)' function for generating random numbers and the appropriate insertion method for the linked list.

Calculate Sum and Average

Initialize two variables, 'sum' and 'count', to zero. Traverse the list, adding each element's value to 'sum' and incrementing 'count' by one. After the traversal, calculate the average by dividing 'sum' by 'count'.

Output Results

Print the sum and the average of the elements in the linked list to display the results of the program.

Key concepts

Random Integer Generation

Generating random integers in programming is a commonly used feature, especially when testing algorithms or when you need to simulate unpredictable behavior. In C++, this can be achieved using the rand() function from the cstdlib library, or the random library which offers more functionality and better randomization. The random library provides various engines and distributions to produce random numbers.

For example, the function std::uniform_int_distribution combined with a random engine like std::mt19937, which is a Mersenne Twister engine, can be used to generate a uniformly distributed sequence of integers within a specified range. Here's how you could use it to generate a random number between 0 and 100:

• Include the headers <#include and <#include .
• Create a static random engine initialized with a seed from a high-resolution clock: static std::mt19937 eng(std::chrono::steady_clock::now().time_since_epoch().count());
• Define the distribution range: std::uniform_int_distribution<> distr(0, 100);
• Generate the random integer: int random_number = distr(eng);

Using the random library improves the randomness quality over the simpler rand() function and is particularly useful in a scenario where we have to ensure the unpredictability of the generated numbers, like in hashing or simulations.

Linked List Implementation

A linked list is a fundamental data structure made up of nodes that together represent a sequence. Each node contains data and a reference (or pointer) to the next node in the sequence. This structure allows efficient insertion and removal of elements from any position within the list, without the need to reallocate or reorganize the entire data structure, as would be necessary with arrays.

In a basic linked list implementation in C++, we typically define a Node class containing a piece of data and a pointer to the next Node. Here's a brief overview of what the node class might contain:

• A data field to store the value.
• A pointer to the next node.

After defining the node, a LinkedList class is created to manage nodes and contain functions like insert(), to add nodes to the list, and traverse(), to go through the list. Linked lists can be singly or doubly linked; in a singly linked list, each node has a single pointer to the next node, while in a doubly linked list, nodes also have pointers to the previous node, which allows backward traversal.

Sum and Average Calculation

Calculating the sum and average of the elements in a linked list involves iterating through each node, collecting and aggregating their values. While traversing a linked list, we often use a loop to visit each node. Here's a simplified approach:

• Initialize a variable named sum to store the cumulative total.
• Create another variable known as count to remember the number of nodes traversed.
• Loop through each node in the linked list, add the node's value to the sum, and increment count by one.
• After the loop finishes, we can calculate the average by dividing the sum by the count.

The calculation of the average should be done with the appropriate numeric type (like a float or double) to ensure that we get a decimal answer if necessary. Casting might be required during the division to avoid integer division if sum and count are both integers; for instance, double average = static_cast(sum) / count;. This process ensures the calculation of an accurate average even when dealing with integer data types.