Question

A retail store grants its customers a maximum amount of credit. Each customer's available credit is his or her maximum amount of credit minus the amount of credit used. Write a pseudocode algorithm for a program that asks for a customer's maximum amount of credit and amount of credit used. The program should then display the customer's available credit. After you write the pseudocode algorithm, convert it to a complete \(\mathrm{C}_{++}\) program.

Short answer

Answer: The C++ program calculates the customer's available credit by subtracting the amount of credit used from the maximum amount of credit (available_credit = max_credit - used_credit). It then displays the calculated available credit using the statement "cout << "The available credit is: " << available_credit << endl;".

Step-by-step solution

Input customer maximum amount of credit and amount of credit used

In this step, get the input from the user for the customer's maximum credit and the amount of credit used.

Calculate the available credit

Compute the available credit by subtracting the amount of credit used from the maximum amount of credit.

Display the available credit

Show the calculated available credit to the user. Now, we will convert the pseudocode into a C++ program: ```cpp #include using namespace std; int main() { //Variable declaration double max_credit, used_credit, available_credit; //Step 1: Input customer maximum amount of credit and amount of credit used cout << "Enter the maximum amount of credit: "; cin >> max_credit; cout << "Enter the amount of credit used: "; cin >> used_credit; //Step 2: Calculate the available credit available_credit = max_credit - used_credit; //Step 3: Display the available credit cout << "The available credit is: " << available_credit << endl; return 0; } ``` The C++ program follows the same steps as the pseudocode, asking for the maximum amount of credit, the amount of credit used, calculating the available credit, and displaying the result.

Key concepts

Pseudocode

Pseudocode is like a recipe for a program. It breaks down the steps needed to solve a problem in plain language, making it easier to translate into actual code. Imagine you're describing a program to someone who knows programming concepts but not your specific code syntax. That's what you're doing with pseudocode. It's a high-level description of an algorithm that omits language-specific details but covers the logic.

• List of Actions: When you write pseudocode, think about the sequence of actions required. In our example, the steps include inputting customer credit details, calculating available credit, and displaying it.
• Easy to Read: Keep it simple! Use common words and straightforward actions. If it reads like a story, you're doing it right.
• Focus on Logic: Highlight the logical flow of operations without worrying about specific programming syntax.

Developing pseudocode helps you focus on problem-solving before you dive into coding. It’s like sketching a blueprint before building something complex.

Algorithm Design

Algorithm design is about creating a step-by-step blueprint to solve problems efficiently. In our example, it's the process of determining how to calculate the available credit from given data effectively. Designing algorithms involves a few key considerations:

• Define the Problem: Clearly understand your task. Here, it involves computing available credit for the customer based on inputs.
• Plan the Steps: Break the big problem into manageable steps, such as inputting data, processing it, and then outputting the results.
• Simplicity and Efficiency: Aim for steps that are straightforward and minimize unnecessary operations. A simple subtraction operation as demonstrated in this exercise is both simple and effective.

A well-designed algorithm ensures that the program executes smoothly and accurately, delivering reliable results.

Input and Output

Input and output operations are vital in any program that interacts with users. They handle how data enters and leaves the program. In C++, these operations are usually performed using streams. Let's break it down:

• Input: Gathers data from the user or another source. For example, the `cin` statement in C++ captures user input, allowing the program to receive the maximum credit and the used credit.
• Output: Delivers results or messages to the user. In C++, `cout` is used to display text or results, such as the available credit calculation in this scenario.

These operations are crucial because they connect the user's intention with the program’s execution, thereby completing the interaction cycle of software.

Variable Declaration

Variable declaration is like setting up containers to hold data within your program. In C++, declaring a variable means specifying its type and giving it a name. This concept is crucial to organize and manage data efficiently.

• Data Types: The type of data a variable will store, such as `int` for integers or `double` for floating-point numbers. Choosing the right type is critical for both performance and correctness.
• Variable Names: These should be descriptive to reflect the data they hold, like `max_credit`, `used_credit`, and `available_credit` in our example.
• Initialization: Sometimes, variables are given initial values during declaration, which can prevent errors from uninitialized data.

By understanding variable declaration, you equip yourself to store and manipulate data effectively, paving the way for clearer and more structured programming.