factorial

factorial.java

import java.util.Scanner;
import java.util.function.Function;

public class Factorialf
{
    // Declare the factorialFn variable outside the factorial method
    static Function<Integer, Integer> factorialFn = new Function<Integer, Integer>() {
        @Override
        public Integer apply(Integer x) {
            if (x == 0) {
                return 1;
            }
            return x * factorialFn.apply(x - 1);
        }
    };

    public static int factorial(int n) {
        return factorialFn.apply(n);
    }

    public static void main(String[] args) {
        try (Scanner scanner = new Scanner(System.in)) {
            int number = scanner.nextInt();
            int fact = 1;

            // Call the factorial function
            fact = factorial(number);

            // Print the result
            System.out.println("The factorial of " + number + " is " + fact);
        }
    }
}