阶乘的两种实现方式

public class Util {

/**     * N的阶乘     *     * @param n     * @return     */    public static int factorial(int n) {        if (n == 1) {            return 1;        } else {            return n * factorial(n - 1);        }    }

public static int factorial2(int n) {        int val = 1;        for (int i = 2; i <= n; i++) {            val *= i;        }        return val;    }

}