package Maths;

public class Factorial {

/* Driver Code */

public static void main(String[] args) {

assert factorial(0) == 1;

assert factorial(1) == 1;

assert factorial(5) == 120;

assert factorial(10) == 3628800;

}

/**

* Calculate factorial N using iteration

*

* @param n the number

* @return the factorial of {@code n}

*/

public static long factorial(int n) {

if (n < 0) {

throw new IllegalArgumentException("number is negative");

}

long factorial = 1;

for (int i = 1; i <= n; factorial *= i, ++i)

;

return factorial;

}

}