35 lines
822 B
Java
35 lines
822 B
Java
|
import java.util.Scanner;
|
||
|
|
|
||
|
|
public class Factorial{
|
||
|
|
|
||
|
|
public static void main(String[] args){
|
||
|
|
Scanner input = new Scanner(System.in);
|
||
|
|
//Prompt user to enter integer
|
||
|
|
System.out.print("Enter a non-negative integer: ");
|
||
|
|
|
||
|
|
//Proceed with factorial calculation only if inputted number is not negative
|
||
|
|
if(input.hasNextInt()){
|
||
|
|
int number = input.nextInt();
|
||
|
|
if (number < 0){
|
||
|
|
System.out.print("Cannot execute. Please enter a non-negative integer: ");
|
||
|
|
number = input.nextInt();
|
||
|
|
} else {
|
||
|
|
//Output of factorial for any non-negative number
|
||
|
|
System.out.println("The factorial of "+number+" will yield: "+factorial(number));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
//Factorial method
|
||
|
|
public static long factorial(int n){
|
||
|
|
|
||
|
|
if (n==0){
|
||
|
|
return 1;
|
||
|
|
} else if (n==1){
|
||
|
|
return 1;
|
||
|
|
} else {
|
||
|
|
return n * factorial(n-1);
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
}
|