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;
    }


}