Testing layout
Diagrams
Combined
flowchart TD
Factorial Subroutine
subgraph factorial
choice -- "1. Factorial" --> inputFactorial["Prompt for number"]
inputFactorial --> callFactorial["Call factorial(n)"]
callFactorial --> checkFactorialNegative{"Is n < 0?"}
checkFactorialNegative -- "Yes" --> factorialError["Throw IllegalArgumentException"]
checkFactorialNegative -- "No" --> initFactorialResult["Set result = 1"]
initFactorialResult --> factorialLoopStart["Initialize i = 1"]
factorialLoopStart --> factorialLoop{"Is i <= n?"}
factorialLoop -- "No" --> factorialEnd["Return result"]
factorialLoop -- "Yes" --> factorialMultiply["Multiply result by i"]
factorialMultiply --> factorialIncrement["Increment i by 1"]
factorialIncrement --> factorialLoop
factorialEnd --> displayFactorialResult["Display Result"]
displayFactorialResult --> menu
end
Fibonacci Subroutine
subgraph fibonacci
choice -- "3. Fibonacci" --> inputFibonacci["Prompt for position"]
inputFibonacci --> callFibonacci["Call fibonacci(n)"]
callFibonacci --> checkFibonacciNegative{"Is n < 0?"}
checkFibonacciNegative -- "Yes" --> fibonacciError["Throw IllegalArgumentException"]
checkFibonacciNegative -- "No" --> checkFibonacciZero{"Is n == 0?"}
checkFibonacciZero -- "Yes" --> fibonacciReturnZero["Return 0"]
checkFibonacciZero -- "No" --> checkFibonacciOne{"Is n == 1?"}
checkFibonacciOne -- "Yes" --> fibonacciReturnOne["Return 1"]
checkFibonacciOne -- "No" --> initFibonacciValues["Set a = 0, b = 1"]
initFibonacciValues --> fibonacciLoopStart["Initialize i = 2"]
fibonacciLoopStart --> fibonacciLoop{"Is i <= n?"}
fibonacciLoop -- "No" --> fibonacciEnd["Return b"]
fibonacciLoop -- "Yes" --> calculateFibonacciC["Set c = a + b"]
calculateFibonacciC --> updateFibonacciValues["Set a = b, b = c"]
updateFibonacciValues --> fibonacciIncrement["Increment i by 1"]
fibonacciIncrement --> fibonacciLoop
fibonacciEnd --> displayFibonacciResult["Display Result"]
displayFibonacciResult --> menu
end
Fib
flowchart TD
subgraph fibonacci
callFibonacci["Call fibonacci(n)"] --> checkFibonacciNegative{"Is n < 0?"}
checkFibonacciNegative -- "Yes" --> fibonacciError["Throw IllegalArgumentException"]
checkFibonacciNegative -- "No" --> checkFibonacciZero{"Is n == 0?"}
checkFibonacciZero -- "Yes" --> fibonacciReturnZero["Return 0"]
checkFibonacciZero -- "No" --> checkFibonacciOne{"Is n == 1?"}
checkFibonacciOne -- "Yes" --> fibonacciReturnOne["Return 1"]
checkFibonacciOne -- "No" --> initFibonacciValues["Set a = 0, b = 1"]
initFibonacciValues --> fibonacciLoopStart["Initialize i = 2"]
fibonacciLoopStart --> fibonacciLoop{"Is i <= n?"}
fibonacciLoop -- "No" --> fibonacciEnd["Return b"]
fibonacciLoop -- "Yes" --> calculateFibonacciC["Set c = a + b"]
calculateFibonacciC --> updateFibonacciValues["Set a = b, b = c"]
updateFibonacciValues --> fibonacciIncrement["Increment i by 1"]
fibonacciIncrement --> fibonacciLoop
end
Prime
flowchart TD
subgraph prime
callPrime["Call isPrime(n)"] --> checkPrimeLessEqual1{"Is n <= 1?"}
checkPrimeLessEqual1 -- "Yes" --> primeReturnFalse["Return False"]
checkPrimeLessEqual1 -- "No" --> primeLoopStart["Initialize i = 2"]
primeLoopStart --> primeLoop{"Is i <= sqrt(n)?"}
primeLoop -- "No" --> primeReturnTrue["Return True"]
primeLoop -- "Yes" --> checkPrimeDivisibility{"Is n % i == 0?"}
checkPrimeDivisibility -- "Yes" --> primeReturnFalse
checkPrimeDivisibility -- "No" --> primeIncrement["Increment i by 1"]
primeIncrement --> primeLoop
end
Factorial
flowchart TD
subgraph factorial
callFactorial["Call factorial(n)"] --> checkFactorialNegative{"Is n < 0?"}
checkFactorialNegative -- "Yes" --> factorialError["Throw IllegalArgumentException"]
checkFactorialNegative -- "No" --> initFactorialResult["Set result = 1"]
initFactorialResult --> factorialLoopStart["Initialize i = 1"]
factorialLoopStart --> factorialLoop{"Is i <= n?"}
factorialLoop -- "No" --> factorialEnd["Return result"]
factorialLoop -- "Yes" --> factorialMultiply["Multiply result by i"]
factorialMultiply --> factorialIncrement["Increment i by 1"]
factorialIncrement --> factorialLoop
end
Code
// Author: Jason Cameron
// Date: 2024-07-22
// Description: This program provides a menu-driven interface for various algorithms including factorial calculation, prime number checking, and Fibonacci number generation.s
import java.util.Scanner;
public class AlgorithmDesign {
/**
* Fetches an integer input from the user. * * @param scanner The scanner object to read input.
* @param prompt The prompt message to display.
* @return The integer the user entered.
*/ public static int getIntInput(Scanner scanner, String prompt) {
String input = scanner.nextLine(); // Read the entire line
try {
return Integer.parseInt(input); // Attempt to convert the input to an integer
} catch (NumberFormatException e) { // If what the user entered is not an integer
System.out.println("Invalid input. Please enter a valid integer."); // Ask the user to enter a valid integer
return getIntInput(scanner, prompt); // Try again
}
}
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
boolean exit = false;
while (!exit) {
// Display the menu
System.out.println("Choose an option:");
System.out.println("1. Calculate Factorial");
System.out.println("2. Check Prime");
System.out.println("3. Find Fibonacci");
System.out.println("4. Exit");
int choice = getIntInput(scanner, "Enter your choice: ");
switch (choice) {
case 1:
// Factorial
System.out.print("Enter a number to find its factorial: ");
int potentialFactorial = getIntInput(scanner, "Enter a number: ");
System.out.println("Factorial of " + potentialFactorial + " is " + factorial(potentialFactorial));
break;
case 2:
// Prime Check
System.out.print("Enter a number to check if it is prime: ");
int potentialPrime = getIntInput(scanner, "Enter a number: ");
if (isPrime(potentialPrime)) {
System.out.println(potentialPrime + " is a prime number.");
} else {
System.out.println(potentialPrime + " is not a prime number.");
}
break;
case 3:
// Fibonacci
System.out.print("Enter the position to find the Fibonacci number: ");
int fibPosition = getIntInput(scanner, "Enter a position: ");
System.out.println("Fibonacci number at position " + fibPosition + " is " + fibonacci(fibPosition));
break;
case 4:
// Exit
exit = true;
break;
default:
System.out.println("Invalid choice. Please select again.");
break;
}
}
scanner.close();
}
/**
* Calculates the factorial of a number. * * @param potentialFactorial The number.
* @return The factorial of the number.
*/ public static long factorial(int potentialFactorial) {
if (potentialFactorial < 0) {
throw new IllegalArgumentException("Number must be non-negative.");
}
long result = 1;
for (int i = 1; i <= potentialFactorial; i++) {
result *= i;
}
return result;
}
/**
* Checks if a number is prime. * * @param potentialPrime The number.
* @return True if the number is prime, false otherwise.
*/ public static boolean isPrime(int potentialPrime) {
if (potentialPrime <= 1) {
return false;
}
for (int i = 2; i <= Math.sqrt(potentialPrime); i++) {
if (potentialPrime % i == 0) {
return false;
}
}
return true;
}
/**
* Finds the Fibonacci number at a specific position. * Note: This implementation uses a long instead of java.math.BigInteger as we have not learned it * @param position The position.
* @return The Fibonacci number at the position.
*/ public static long fibonacci(int position) {
if (position < 0) {
throw new IllegalArgumentException("Position must be non-negative.");
}
if (position == 0) {
return 0;
}
if (position == 1) {
return 1;
}
long a = 0, b = 1, c;
for (int i = 2; i <= position; i++) {
c = a + b;
a = b;
b = c;
}
return b;
}
}