Mastering CS50: Step by Step Cash Solution for Beginners

Table of Contents

1. Introduction
2. Problem Overview
3. Example Explanation
4. Logic behind the Program
5. The Distribution Code
6. How to Get User Input
7. Calculating Quarters
8. Calculating Dimes
9. Calculating Nickels
10. Calculating Pennies
11. Testing the Program
12. Conclusion

Introduction

In this article, we will be discussing CS50 problem set one cache. We will cover the updated version for 2022 and provide an in-depth explanation of the problem and its solution. This article aims to help beginners understand the logic behind the program and guide them through the code step by step. By the end of this article, You will have a clear understanding of how to calculate the minimum number of coins needed to make up a certain amount of cents.

Problem Overview

The objective of the cache problem is to ask the user for a specific number of cents and output the minimum number of coins required to make up that amount. The program assumes that the coins available are quarters, dimes, nickels, and pennies. For example, if the user inputs 68 cents, the program should output that it requires two quarters, one dime, one nickel, and three pennies, totaling seven coins.

Example Explanation

To illustrate the problem, let's use the example of the user inputting 68 cents. The logic for calculating the minimum number of coins goes as follows:

1. Is the amount greater than 25? If yes, subtract 25 and add one quarter.
2. Subtract 25 from the remaining amount and check again.
3. Repeat until the amount is no longer greater than 25.
4. Move on to dimes. Subtract 10 if the amount is greater than 10, and add one dime.
5. Repeat the process for nickels and pennies, subtracting their respective values and adding them to the count if the amount is greater.

Based on this logic, the program should calculate the need for two quarters, one dime, one nickel, and three pennies to make up 68 cents.

Logic behind the Program

The program follows a simple logic to calculate the minimum number of coins. It first asks for the amount of cents owed by the customer. Then, it calculates the number of quarters needed by dividing the amount by 25 and subtracting that from the remaining cents. The process continues for dimes, nickels, and pennies, updating the remaining cents and adding the respective coins to the count. Finally, the program returns the total number of coins needed.

The Distribution Code

The distribution code provided by CS50 includes the necessary header files and some function prototypes. It Prompts the user for the amount of cents owed and calculates the number of quarters, dimes, nickels, and pennies using functions like calculate_quarters, calculate_dimes, calculate_nickels, and calculate_pennies. Finally, it adds up the total number of coins and prints the result.

How to Get User Input

To get user input for the amount of cents owed, we need to Create a function that uses the get_int function provided by CS50. We can prompt the user for the input and use a do-while loop to validate that the input is a positive number. The function should return the value of cents entered by the user.

Calculating Quarters

To calculate the number of quarters, we need a loop that subtracts 25 from the remaining cents and adds one to the count every time the remaining cents are greater than or equal to 25. This loop will Continue until the remaining cents are no longer greater than or equal to 25. Finally, the function should return the total count of quarters.

Calculating Dimes

The logic for calculating dimes is similar to that of quarters. We need a loop that subtracts 10 from the remaining cents and adds one to the count every time the remaining cents are greater than or equal to 10. The loop will continue until the remaining cents are no longer greater than or equal to 10. Finally, the function should return the total count of dimes.

Calculating Nickels

The process for calculating nickels follows the same logic as quarters and dimes. We need a loop that subtracts 5 from the remaining cents and adds one to the count every time the remaining cents are greater than or equal to 5. The loop will continue until the remaining cents are no longer greater than or equal to 5. Finally, the function should return the total count of nickels.

Calculating Pennies

Calculating pennies is the last step in determining the minimum number of coins needed. We need a loop that subtracts 1 from the remaining cents and adds one to the count every time the remaining cents are greater than or equal to 1. The loop will continue until the remaining cents are no longer greater than or equal to 1. Finally, the function should return the total count of pennies.

Testing the Program

To test the program, we can compile it using make cash and run it using ./cash. We can input various amounts, such as 68 and 99, to check if the program correctly calculates the minimum number of coins needed. Additionally, we can use the check50 command to verify if the code is correct and check for any style issues.

Conclusion

In this article, we have discussed CS50 problem set one cache and provided a detailed explanation of the problem and its solution. We have covered the logic behind the program and guided you through the code step by step. By following the provided instructions, you can now calculate the minimum number of coins needed to make up a certain amount of cents. Remember to check for correctness and style before submitting your code.

Highlights:

• Explained the CS50 problem set one cache
• Provided a step-by-step guide to solve the problem
• Discussed the logic behind the program
• Demonstrated how to calculate the minimum number of coins needed
• Implemented user input validation
• Tested the program with different inputs
• Considered correctness and code style for submission

FAQ

Q: What happens if the user inputs a negative number for cents owed? A: The program will prompt the user to input a positive number and will continue to do so until a positive value is entered.

Q: What if the user inputs a non-numeric value for cents owed? A: The program will throw an error and ask the user to enter a valid numeric value.

Q: Can this program calculate the minimum number of coins for any given amount? A: Yes, the program can calculate the minimum number of coins for any positive integer value entered by the user.

Q: How can I check if my code is correct and follows the required coding style? A: You can use the check50 command provided by CS50 to check if your code is correct. To check for style, you can use the style50 command. Both commands will provide feedback on any issues found in your code.

Q: Can I submit my code without running the correctness and style checks? A: It is recommended to run the correctness and style checks before submitting your code to ensure it meets the required standards. However, it is possible to submit your code without running these checks.