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Merge pull request #52 from MarcHines/patch-1

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Update Factorial.java
This commit is contained in:
Anup Kumar Panwar
2017-06-01 06:34:18 +05:30
committed by GitHub
parent 3907716e1f 149e5d2abc
commit e8e65504bf
1 changed files with 26 additions and 29 deletions
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33
Factorial.java
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@ -1,10 +1,11 @@
package factorial;
import java.util.Scanner; import java.util.Scanner;
/** /**
* This program will print out the factorial of any non-negative * This program will print out the factorial of any non-negative
* number that you input into it. * number that you input into it.
* *
* @author Unknown * @author Marcus
* *
*/ */
public class Factorial{ public class Factorial{
@ -16,19 +17,22 @@ public class Factorial{
*/ */
public static void main(String[] args){ public static void main(String[] args){
Scanner input = new Scanner(System.in); Scanner input = new Scanner(System.in);
//Prompt user to enter integer
System.out.print("Enter a non-negative integer: "); System.out.print("Enter a non-negative integer: ");
//Proceed with factorial calculation only if inputted number is not negative //If user does not enter an Integer, we want program to fail gracefully, letting the user know why it terminated
if(input.hasNextInt()){ try{
int number = input.nextInt(); int number = input.nextInt();
if (number < 0){
System.out.print("Cannot execute. Please enter a non-negative integer: "); //We keep prompting the user until they enter a positive number
while(number < 0){
System.out.println("Your input must be non-negative. Please enter a positive number: ");
number = input.nextInt(); number = input.nextInt();
} else {
//Output of factorial for any non-negative number
System.out.println("The factorial of "+number+" will yield: "+factorial(number));
} }
//Display the result
System.out.println("The factorial of " + number + " will yield: " + factorial(number));
}catch(Exception e){
System.out.println("Error: You did not enter an integer. Program has terminated.");
} }
input.close(); input.close();
} }
@ -40,14 +44,7 @@ public class Factorial{
* @return The factorial of the number * @return The factorial of the number
*/ */
public static long factorial(int n){ public static long factorial(int n){
if(n == 0 || n == 1) return 1;
if (n==0){ return n * factorial(n - 1);
return 1;
} else if (n==1){
return 1;
} else {
return n * factorial(n-1);
}
} }
} }