寫(xiě)一個(gè)方法，輸入任意一個(gè)整數(shù)，返回它的階乘

/**

     * 獲得任意一個(gè)整數(shù)的階乘

     * @param n

     * @return n!

     */

    public int factorial(int n)

    {

       //遞歸

       if(n==1)

       {

           return 1;

       }

       return n*factorial(n-1);

       //非遞歸                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     

//     int multi = 1;

//     for (int i = 2; i <= n; i++) {

//         multi*=i;

//     }

//     return multi;

    }